【作者】 张薇；

【导师】 田维坚；

【作者基本信息】 中国科学院研究生院（西安光学精密机械研究所） ， 光学工程， 2009， 博士

【摘要】 随着现代光学仪器的发展,对光学变焦技术的需求愈来愈广泛,然而现有的变焦系统设计方法及结构限制了其在微小型系统中的应用,同时存在易磨损、寿命低的缺点。液体透镜是一种新型的光学元件,它不需采用任何移动组件,具有一定的自主变焦能力。将这种元件应用于变焦系统,可以完成传统光学元件难以完成的功能,避免传统变焦系统结构复杂、易磨损的缺点,推动变焦系统向小型化、灵巧化发展。本文以液体透镜技术及其在微型变焦距系统中的应用为中心展开研究。重点针对两种液体可变焦透镜技术——基于填充液体表面曲率变化的液体透镜和基于电润湿效应的液体透镜及其应用,进行了深入研究。主要完成了以下工作:首先,以几何光学及像差理论为基础,对两种液体透镜进行了成像模型、像差理论分析,讨论了两种液体透镜在焦距变化时的像差变化情况。针对普通液体透镜一旦所需的光焦度确定,就不再有可用于像差校正的自由度问题,提出一种折衍混合液体透镜,可在不改变透镜重量、尺寸和结构稳定性基础上,增加设计自由度,并利用衍射光学的分析方法对其成像性质进行了讨论,结果表明:加入衍射面后,可以提高透镜的MTF值,有利于透镜的优化。其次,结合现有材料、工艺技术,分别设计和制作了两种普通液体可变焦透镜,并对其进行了检测。考察了材料、重力、密度及温度变化对液体透镜性能的影响。利用有限元方法分析了液体透镜受重力影响的形变情况,考察了透镜口径、可变形表面曲率及填充液体密度与形变的关系;分析了两种液体密度失配对电润湿型液体透镜光焦度的影响;提出了透镜光焦度随温度变化的补偿方法。最后,对液体透镜在微型变焦领域的应用进行了探索。提出了一种新的无移动组件变焦系统设计思路。以液体透镜(包括折衍混合的液体透镜)为核心元件,设计了可调焦内窥系统、二元变焦内窥系统和连续变焦手机镜头三种不同类型的微型光学系统,在满足系统尺寸及使用功能的基础上,初步实现了系统中无移动组件的调焦、变焦功能。更多还原

【Abstract】 With the development of the modern optical instrument, the optical zoom system has been adopted more widely. But the conventional zoom system is always limited by its designing method and complicated structure in application to micro system. And it also has the disadvantages of easy to be abrased and short using life. Liquid lens is a kind of novel optical device, which can realize active zooming without any moving elements. The liquid lens can provide many new functions which the normal lens can not realize. By utilizing this device, zoom camera can be designed more miniature and smart than before and avoid the objections of complicated structure and short using life.The liquid lens technology and its application in the micro zoom system were discussed in this dissertation. The discussion focuses on two kinds of liquid lens, which include the liquid-filled membrane lens and the electrowetting effect based liquid lens. The main work completed includes:Firstly, the imaging principle and the aberration of the two kinds of liquid lens were analyzed based on the geometrical optical theory and the aberration theory. The aberrations of the liquid lens were studied, when the focal power shifted. A kind of hybrid diffractive-refractive liquid lens was presented to solve the problem that there was no designing freedom can be used to adjust the aberration, when the lens’s focal power needed was confirmed. The hybrid diffractive-refractive liquid lens can offer a freedom to adjust the aberration of the system but without increasing its volume and weight, and depressing the stability of its structure. And the imaging principle of the hybrid liquid lens was analyzed based on the diffractive theory, which showed that the Modulation Transfer Function (MTF) of the liquid lens can be increased when the diffractive surface was added. Secondly, two kinds of liquid lens had been fabricated in laboratory and tested. The influence of the material, gravity, liquid density and environmental temperature on the imaging quality was analyzed. The shape deformation of the liquid-filled membrane lens caused by the gravity was calculated by the Finite Element Analysis method. And the impact on the deformation of the lens’s aperture, the surface curvature and the density of the filled liquid was studied. The focal power change was analyzed, which was caused by the inconsistence of the density of the two kinds of liquid in electrowetting based liquid lens. And the approach of how to compensate the focal power shift caused by the temperature altering was proposed.Finally, the application of the liquid lens to micro zoom optical system was researched. A method of designing zoom optical system without any moving lens was demonstrated, by using the liquid lens and the hybrid diffractive-refractive liquid lens as core elements, which can avoid the disadvantages of complicated structure and easy to be abrased in the conventional zoom system. And three kinds of micro optical instrument including auto-focusing endoscope system, bifocal zoom endoscope system, and zooming mobile phone lens were designed, which not only realized the function of auto-focusing or zooming in the system, but also satisfied the requirements of the structure and application.更多还原