基于物像视差比较的透镜组焦距测量系统的设计

透镜组的焦距可以用测节器来测量,利用测节器测量的优点就是直观,在不用测节器的情况下,我们还可以用牛顿公式来测量,在利用牛顿公式时,需要知道焦点、物点、像点位置,常用的方法是对成像清晰程度进行判断,不同的人判断是不一样的,误差较大。文中采用物像视差比较的方法来判断,首先介绍整个测量系统,再介绍针尖系统,最后利用物像视差比较的方法,测出焦点、物点、像点位置,最终得到透镜组的焦距,相对偏差是0.13%,同时用测节器测量透镜组焦距,相对偏差0.45%。可以看出用物像视差比较的方法测量的结果更精确。

Design of Lens Group Focal Length Measurement System Based on Object-Image Parallax Comparison

The focal length of lens group can be measured by nodal slide.The advantage of using nodal slide is intuitive.Without nodal slide,we can also measure by Newton formula.When using Newton formula,we need to know the position of focus,object point and image point.The usual method is to judge the clarity of the image.Different people′s judgment is different,and the error is large.In this paper,the method of object-image parallax comparison is used to judge.First,the whole measuring system is introduced,then the pinpoint system is introduced.Finally,the focus,object point and image point positions are measured by the methodof object-image parallax comparison.Finally,the focal length of lens group is obtained.The relative deviation is 0.13%.At the same time,the focal length of lens group are measured by a nodal slide,and relative deviation is 0.45%.It can be seen that the results measured by the method of object-image parallax comparison are more accurate.