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。
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.
出处
《光电工程》
CAS
CSCD
北大核心
2004年第12期34-37,42,共5页
Opto-Electronic Engineering
基金
国家自然科学基金资助项目(90206029
60178033)
中国科学院知识创新工程重大项目(KJCX1-SW-07-03)
关键词
自动调焦
角度调焦
椭偏成像
倾斜镜
Automatic focusing
Angle focusing
Imaging ellipsometry
Tilt mirror
