【作者】 刘璐；

【导师】 杨连祥； 王永红；

【作者基本信息】 合肥工业大学 ， 光电信息工程， 2019， 硕士

【摘要】 自动对焦技术在光学影像测量中得到广泛应用,由于各种成像和测量要求的不同,对自动对焦技术的要求也不同。在工业显微测量中,环境微动和振动会使被测物偏离显微镜的焦面,这时自动对焦技术在光学显微镜中就显得至关重要。本文针对液晶面板生产中缺陷显微检测的自动对焦问题,设计了一套基于投影条纹的自动对焦显微镜系统,对设计的光路进行仿真,验证系统可行性;并搭建实验装置,研究分析系统关键技术参数,最后设计组装完成一套自动对焦显微镜系统。具体的研究工作如下:(1)介绍了国内外自动对焦方法的发展和国内外研究现状,阐述了本文的研究意义。对现有的自动对焦技术进行分类,阐述了光学显微镜的原理,并从成像原理出发分析了对焦的几种方法,研究构建了光学显微镜的调焦过程数学模型。(2)设计基于条纹投影的自动对焦显微镜系统,使用Tracepro对该系统光路进行仿真,分析不同的清晰度评价函数的优劣,对处理光栅图的清晰度评价函数进行选择;通过仿真系统对不同的被测物进行对焦,验证基于条纹投影的自动对焦显微镜系统的可行性。(3)搭建使用数字投影光栅的实验系统,分析光栅周期对系统对焦范围的影响,分别使用等周期光栅、变周期光栅和不同物镜进行实验,并研究获取最优对焦性能的系统技术参数;设计加工完成数字投影光栅显微镜自动对焦系统的机械结构,对系统进行组装、调试和测试,验证系统的对焦性能;最后对系统技术进行总结,分析系统的误差来源。更多还原

【Abstract】 Autofocus technology is widely used in optical image measurement,and the requirements for autofocus technology vary depending on various imaging and measurement requirements.In industrial microscopic measurements,environmental fretting and vibration can cause the object to be measured off the focal plane of the microscope,and autofocus technology is critical in optical microscopy.In this paper,an autofocus microscope system based on projection stripe is designed for the autofocus problem of defect microscopy in liquid crystal panel production,and the design of the optical path is simulated to verify the feasibility of the system;The system was built on the test bench to study the key parameters,the design and assembly completed an autofocus microscope system finally.The specific research work is as follows:(1)Introduced the development of autofocus methods at home and abroad and the research status at home and abroad,and expounded the significance of this paper.The existing autofocus technology is classified,the principle of optical microscope is expounded,and several methods of focusing are analyzed from the imaging principle.The mathematical model of the focusing process of optical microscope is constructed.(2)Designing an autofocus microscope system based on fringe projection,using Tracepro to simulate the optical path of the system.Analyze the advantages and disadvantages of different definition evaluation functions,and select the resolution evaluation function for processing raster images.The feasibility of the fringe projection-based autofocus microscope system was verified by focusing the different objects under the simulation system.(3)Build an experimental system using digital projection grating,analyze the influence of grating period on the focusing range of the system,experiment with equal period grating,variable period grating and different objective lenses,and study the system technical parameters to obtain the optimal focusing performance;Design and process the mechanical structure of the digital projection grating microscope autofocus system,assemble,debug and test the system to verify the focusing performance of the system;Finally,the system technology is summarized and the error source of the system is analyzed.更多还原