倾斜镜面成像自动调焦方法.pdf

第31卷第12期 光电工程 Vol.31,No.12 2004年12月 Opto-Electronic Engineering Dec,2004 文章编号：1003-501X(2004)12-0034-04 倾斜镜面成像的自动调焦方法 1,2 1 孟永宏 ，靳 刚 (1. 中国科学院力学研究所国家微重力实验室，北京 100080; 2. 中国科学院研究生院，北京 100039) 摘要：倾斜镜面成像系统的像面与光轴倾斜，仅利用轴向自动调焦无法实现像面整体清晰。为此 提出一种基于图像清晰度判断的自动调焦方法。该方法将轴向调焦与角度调焦相结合，通过步进 方式平移和旋转像接收面，利用离焦函数判断聚焦情况，采用数据拟合回归的方法实现了像面整 体清晰。该方法在椭偏成像系统的应用结果验证了其有效性，调焦精度达到微米量级。 关键词：自动调焦；角度调焦；椭偏成像；倾斜镜 中图分类号：TB851 文献标识码：A An automatic focusing method for the imaging of an illumination–tilted specular-reflection imaging system MENG Yong-hong, JIN Gang (1. State Key Laboratory of Microgravity ,Institute of Mechanics , the Chinese Academy of Sciences, Beijing 100080, China; 2. Graduate School of the Chinese Academy of Sciences, Beijing 100039, China) Abstract ：The image plane of illumination-tilted specular reflection imaging system(TSIS) is not perpendicular to the optical axes, which makes auto-focusing in optical axes direction unavailable. In order to solve this problem, an auto-focusing method based on image brightness gradient sharpness function is proposed, which combines auto-focusing in optical axes direction and angle-tilted auto-focusing by step moving and rotating imaging sensor successively. The auto-focusing method can make planar image clearly in whole image plane by using defocusing function and data fitting method. Experiment result from imaging ellipsometry system demonstrates its availability and its precision reaches micron order. Key w