Abstract:In machine vision, due to the influence of painting, coating, glass, packaging film or other reflective materials on the surface of the workpiece, industrial cameras can not acquire highquality images successfully.Because of the low contrast of images or the incomplete presentation of key features, it often leads to the occurrence of false detection, misjudgment, low precision and instability in a machine vision system, and even output wrong data. In order to solve the above problems, the experiments of character defect detection on capacitor surface and character detection on keyboard surface covered with transparent packaging film were taken as examples,the polarizing plates were integrated with the analyzer plates by using the polarization characteristics of light.By using the improved polarization light source, the strong reflection phenomenon in machine vision was effectively eliminated, and the images with clear character features were obtained