基于局部焦距追迹计算优化的广角镜头设计方法  

Design Method of Wide Angle Lens Based on Optimization of Local Focal Length through Ray Tracing

作　　者：陈露 刘辉 封志明 陈熙源[2] 张帆 许宁晏 袁群[3] 高志山[3] CHEN Lu;LIU Hui;FENG Zhiming;CHEN Xiyuan;ZHANG Fan;XU Ningyan;YUAN Qun;GAO Zhishan(Jiangsu Institute of Metrology(Jiangsu Energy Measurement Data Center),Nanjing 210023,China;School of Instrument Science and Engineering,Southeast University,Nanjing 210018,China;School of Electronic and Optical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]江苏省计量科学研究院(江苏省能源计量数据中心),南京210023 [2]东南大学仪器科学与工程学院,南京210018 [3]南京理工大学电子工程与光电技术学院,南京210094

出　　处：《光子学报》2024年第3期91-99,共9页Acta Photonica Sinica

基　　金：国家自然科学基金(No.62305160);中国博士后科学基金(No.2023M731399);江苏省卓越博士后计划(No.JB23056);国家市场监督管理总局科技计划项目(No.2023MK038)。

摘　　要：将焦距的内涵由零视场拓展至全视场,局部焦距可被用来表征各视场处极小视场角增量光线对应的像高增量,畸变则等效为随视场变化的局部焦距。继而,将局部焦距引入光学系统的设计过程用于畸变的表征与控制,可获得算测融合的效果。针对鱼眼镜头大视场、中央视场分辨率高且无畸变的成像目标,通过对局部焦距的追迹计算和优化控制,设计了全视场角160°,50%中央视场满足f-tanθ等线投影的鱼眼镜头。针对有限物距曲面物体复杂成像场景,通过对局部焦距的调控变换,为多种曲率半径数值的凸、凹物面设计了相应的广角镜头,满足了120°视场范围内物方等分辨率投影映射的效果。The projection model regulates the mapping relationship between the object and image for the imaging system,where they are related by the focal length.The distortion is defined as the departure from the similarity between the object and image,or the departure from the targeted projection model.Thus,the focal length and distortion represent the actual relationship of the optical system.The focal length is the most important and basic parameter of an optical system,which is theoretically defined utilizing the“minor aperture method”.According to the regulation of“minor aperture method”,the ray close and parallel to the optical axis is traced,and then its angle of convergence after passing through the optical system is recorded for focal length calculation.This regulation is easy to execute during the optical design process but hard to execute for the measurement of the built performance of the optical system.The“minor image height method”is the frequently adopted regulation for focal length measurement,in which ray with minor field of view is traced,and the corresponding image height is recorded for focal length calculation.The“minor image height method”is easy to execute for both design and measurement,and aligns well with the definition of projection.Therefore,if the definition of the focal length is developed from the on axis field of view to the off-axis field of views,then the local focal length which is a field dependent parameter is involuntary generated.And the“minor image height method”is adopted for local focal length definition,in which the image height increment for a minor angle increment is regulated for each field of view.Moreover,the distortion is represented by the variable local focal length for different field of views.And then,the local focal length can be adopted in the process of optical system design for distortion control,for its calculation in the design coincides well with the measurement in the experiment,which is the outstanding priority according to its regulation.A f

关 键 词：光学设计 局部焦距 光线追迹 广角镜头 

分 类 号：O439[机械工程—光学工程]