用于工业测量中变倍双远心光学系统设计

Optical Design of Zoom Double Telecentric System for Industrial Measurement

曲线磨床加工的工件种类繁多。对于检测不同种类和尺寸的工件,要求的检测精度不同,传统的曲线磨削在线检测系统需要更换不同的光学组件。为解决以上问题,设计了一款变倍双远心光学系统,通过对变倍远心镜头的倍率定档标示,实现不同尺寸工件的不同精度检测要求。同时具有对像面物面位移不敏感和可连续变倍的优点。物方视场为0.02～40mm,光学系统放大倍率为-0.25X～-0.5X。使用ZEMAX软件设计优化其光学系统,最终该系统各视场畸变均小于0.3%;全视场MTF在145lp/mm处均大于0.1,接近衍射极限;远心度均小于1°。对于0.02～20mm,20～30mm,30～40mm尺寸范围的工件,检测精度分别可以达到0.02mm,0.03mm,0.04mm,达到了工业上检测要求。

There are many kinds of workpieces processed by curve grinder. The required detection accuracy is different for different types and sizes of workpieces,different optical components needs to be replaced in the traditional on-line inspection system for curve grinding. In order to solve the above problems,a double telecentric zoom lens system was designed. By marking the magnification of the variable magnification telecentric lens,the different precision detection requirements of the workpieces with different sizes are realized. At the same time,it is insensitive to object and image displacements,and the magnification can be continuously changed. The object field of view is 0.02～40 mm;and the magnification of the optical system is-0.25 X～-0.5 X. The ZEMAX software is used to design and optimize the optical system. The distortion of each field of view of the system is less than 0.3%;the MTF of the whole field of view is greater than 0.1 at 145 lp/mm; which is close to the diffraction limit; and the telecentricity is less than 1°.For the workpieces in the size range of 0.02 mm～20 mm, 20 mm～30 mm, 30 mm～40 mm, the detection accuracy can reach0.02 mm,0.03 mm,and 0.04 mm respectively. The detection requirements are met.