Optical Design Of Three-in-one Zoom Digital Microscope System

Zoom microscope can change magnification continuously, which satisfies the demand of observe outline of an object as well as details. Digital microscopy can realize digital information recording and processing.The thesis mainly discusses the optical design of three-in-one zoom digital microscope system. The system combine zoom microscope with illuminating apparatus and image sensor. Based on the theory of zoom optical system, we design some kinds of zoom digital microscope systems and analysis the shortcomings. Finally we obtained a good performance zoom digital microscope system.The thesis firstly describes the principle of zoom optical system and the difference between mechanically compensated and optically compensated. Besides, the thesis describes the microscope illumination and digital microscope system briefly. According to the problem of contrast differences in every zoom position, we present some solutions.Then the thesis describes the optical design of a series of zoom digital microscope systems. They are designed based on two-component mechanically compensated zoom system. We assemble the prototypes and analyze the shortcomings. Then based on four- component mechanically compensated zoom system, we assemble another zoom digital microscope system. It has the magnification from 0.25 to 1.6, and has a good performance of aberration and contrast. The microscope system equip with illuminating apparatus and image sensor. The system has a maximum NA of 0.032 and the distortion is less than 0.5%. Its working distance is 67.86 mm and conjugate distance is 190 mm.Finally the thesis designs another two zoom digital microscope systems. One has the magnification from 0.7to 5.6. The other can adapt the infinity microscope objectives, which can obtain zoom ratio of 160 times.