双凸透镜系统成像规律分析

ANALYSIS OF THE IMAGING REGULARITIES OF DUAL CONVEX LENSES SYSTEM

显微镜的组装是大学物理实验教学中一个非常重要实验内容,实验中要求物镜与目镜之间的距离(即显微镜的镜筒长度)设定为一定值.由于学生对凸透镜成像规律及显微镜成像原理等相关知识理解不够透彻,不少同学对镜筒长度为一定值这一要求存在疑惑.本文根据几何光学的知识,推导出不同镜筒长度双凸透镜系统的成像规律,并利用凸透镜成像公式计算出相应的放大倍率和成像位置.结果表明,两凸透镜之间的距离在成像过程中起着关键的作用,当二者之间的距离太大或太小时,均无法实现对物体进行放大的目的.

Assembly of a microscope is an important experiment content of the college physical experiment.During the experimental operation,the distance between the objective and the eyepiece is fixed at a certain value.Many students cannot understand this requirement and change the distance casually which usually leads to an experimental failure.In this paper,the imaging regularity of dual convex lenses is analyzed by using geometrical optics.Both the amplified factor and the location of the image are calculated suing the imaging equation of a convex lens.The results show that the distance between the two lenses is critical to the microscope system.The system cannot magnify the object when the distance between the objective and the eyepiece is too large or too small.