光学学报, 2017, 37 (6): 0622001, 网络出版: 2017-06-08
基于Q-type非球面的电子内窥镜物镜光学系统设计 下载: 678次
Optical System Design of Electronic Endoscope Objective with Q-type Aspheres
光学设计 内窥镜光学系统 Q-type非球面 非球面加工 装配敏感性 optical design endoscope optical system Q-type aspheres aspheric fabrication assembly sensitivity
摘要
采用具有“负-正”形式的反远距结构作为初始结构, 利用Q-type非球面设计了一款工作在可见光波段的电子内窥镜物镜(EEO)光学系统, 其全视场为110°, 焦距为1 mm, F数为3.3, 最大通光孔径为3 mm, 系统总长为7.89 mm。该光学系统由6片透镜组成, 包括两组双胶合透镜和一片两面均为Q-type非球面的镜片。设计结果表明, 在奈奎斯特空间频率143 lp/mm处的调制传递函数(MTF)高于0.4, 接近衍射极限。为验证Q-type非球面在EEO系统设计中的优越性, 在相同计算平台与结构参数下设计了一款包含幂级数(PS)非球面的EEO系统, 对两者进行了分析比较。结果表明, Q-type非球面具有更强的系统像差校正能力, 且有利于提高系统的优化设计效率; 设计得到的Q-type非球面与其最接近球面之间的偏离量非常小, 有利于提高非球面光学元件的加工效率与检测精度, 降低成本; 同时Q-type非球面EEO系统的装配敏感性更低, 有利于提高系统的装配效率。
Abstract
By using the retrofocus structure with a “negative-positive” form as the initial structure, we design an electronic endoscope objective (EEO) optical system with Q-type aspheres working in the visible light band, whose total field of view is 110°, focal length is 1 mm, F number is 3.3, maximum clear aperture is 3 mm, and total length is 7.89 mm. The optical system is composed of six pieces of lenses, including two cemented doublet and one lens with Q-type aspheres of both sides. The design results show that the modulation transfer function (MTF) values are higher than 0.4 at Nyquist spatial frequency of 143 lp/mm, which is approaching the diffraction limit. For validating superiority of Q-type aspheres in EEO system design, an EEO system is designed with power series (PS) aspheres in the same computing platform and with the same structure parameters. The comparison results show that Q-type aspheres have stronger ability to correct the aberration of the system, and they are helpful to improve the efficiency of system optimization. The aspheric departure between the designed Q-type aspheres and their closest spheres is very little, which is beneficial to enhance the detection precision and working efficiency of aspheric optical components, and the cost can be reduced. The designed EEO system with Q-type aspheres has lower assembly sensitivity, which helps to improve the system assembly efficiency.
李闯, 薛常喜, 杨红芳, 张然. 基于Q-type非球面的电子内窥镜物镜光学系统设计[J]. 光学学报, 2017, 37(6): 0622001. Li Chuang, Xue Changxi, Yang Hongfang, Zhang Ran. Optical System Design of Electronic Endoscope Objective with Q-type Aspheres[J]. Acta Optica Sinica, 2017, 37(6): 0622001.