镜面偏心测量光学系统设计及其杂光分析

为了解决现有镜面偏心测量设备存在的问题,本文研究了一种采用切换镜头和调焦相结合的方法来设计的镜面偏心测量光学系统,使用这个光学系统,既能使被测镜面的曲率半径扩展到-∞~+∞范围,又能保证测量精度。通过Lighttools软件对这个光学系统进行光线追迹,分析其杂光分布,结果表明:准直镜头内部多次反射产生的杂光强度很低,可以忽略。而当被测镜头中存在相邻球心像距的镜面时,产生的杂光强度比较大,在后续的图像处理过程中,必须增强目标图像的对比度。利用研制的镜面偏心测量设备进行测量实验,结果进一步验证了杂光分析的正确性。

Design of lens centering error measuring optical system and stray light analysis

To improve current equipments in the market, a lens-eccentricity-measuring optical system that combines the focusing method and lens-switching method is designed in this paper. This optical system can be used to measure lens with curvature radius from -∞ to +∞, as well as maintain the test accuracy. Lighttools software is used to trace the light ray and analyze stray light distribution of this optical system. Results show that the intensity of the stray light after multiple reflection inside the collimated lens is low and negligible. The stray light intensity becomes stronger when the image distances of sphere centers are nearby in the testing lens. So in the later image processing, the contrast of target images must be strengthened. Measurement experiments are done by using the equipment with this optical system. All the experimental results further verify the correctness of stray light analyzing.