适用显微镜质量测试的高分辨率测量镜头设计

High resolution measurement lens design for microscope quality testing

利用Zemax光学设计软件设计了一款适用于光学成像尺寸为38mm的互补金属氧化物半导体(CMOS)型工业相机的高分辨率测量镜头,该工业相机用于自动化定量分析检测显微镜像差。通过数码图像处理的方式去评判显微镜物镜性能的好坏。在满足性能要求基础上,对普通的测量镜头结构加以优化,使得测量镜头拥有非常高的分辨率。该镜头焦距为36mm,后工作距约为32mm,视场像面高度为36mm,在90lp/mm处,中心视场调制传递函数(MTF)值大于0.45,边缘视场MTF值大于0.25。

A high-resolution measurement lens for a complementary metal-oxide semiconductor （CMOS） industrial camera with an optical imaging size of 38 mm was designed using the Zemax optical design software. The industrial camera was used for automated quantitative analysis to detect microscopic aberrations. The performance of the microscope objective lens is judged by the digital image processing method. On the basis of satisfying the performance requirements？ the ordinary measurement lens was optimized,and the lens structure was optimized so that the measurement lens has higher resolution. The effective focal length of the system is 36 mm. Back working distance is about 32 mm？ the field-of-view height is 36 mm. At 90 lp/mm？ its modulated transfer function （MTF） of center field is greater than 0. 45 and the MTF value of edge field is greater than 0. 25.