【作者】 张文字；

【导师】 余飞鸿；

【作者基本信息】 浙江大学 ， 光学工程， 2010， 博士

【摘要】 论文通过回顾传统成像光学和非成像光学中光线的折/反射过程,对于光学曲面斜率角在光学系统中的作用进行了重新认识。无论是在成像光学还是非成像光学中,光学曲面斜率角都起了重要的作用,所有光线的汇聚、发散以及光能量的再分配过程都是直接经由它完成的。相对于传统非成像器件优化中常用的基于曲面面型控制的优化方法,本论文首次提出了一种基于曲面斜率角控制的优化方法。该方法可以有效地避免传统的基于曲面面型控制的优化方法中存在的三个问题,可更加有效地控制优化目标逼近设计目标。论文通过用于普通照明的非成像反射器设计的实例比较对曲面斜率角控制优化方法的优势进行了验证。论文在微型投影光引擎照明系统设计中应用了基于曲面斜率角控制的优化方法。本论文首先设计了一款基于单片集光镜进行LED光束整形的嵌入式CF-LCoS微型投影光引擎。该光引擎结构简洁、组装制造方便、成本较低,同时又保持了较高的光效率以及投影画面均匀度,非常适合在手机等移动平台上的批量应用。论文首次应用曲面斜率角控制优化方法对基于TIR透镜的光引擎照明系统进行优化,在零件成本降低的同时,也减小了光引擎的系统尺寸。另外,论文也首次应用曲面斜率角控制优化方法对基于集光镜和柱面镜生成椭圆光斑的照明系统进行了优化,虽然该系统尺寸稍微偏大,但是经过优化后的照明系统其光能利用率比单片集光镜照明方案提升了至少10%。椭圆光斑照明系统的最大优点在于它能为不同长宽比或大长宽比的显示芯片提高同样的光能利用效率和照度均匀性。论文更进一步研究了基于白光LED照明的独立式CF-LCoS微型投影光引擎设计。论文首先通过数学推导分析了复眼和光棒二种传统匀光方式的差异点和共同点。二种匀光方式都是通过对光束角的分割和积分来实现均匀照明,而光棒由于其独特的“镜向积分”过程使其在面对奇对称性光源时保持了与偶对称性光源时相同的匀光能力,这一点是复眼匀光方式所不具备的。针对这二种传统匀光照明系统的不足之处,本论文提出了一种基于光棒匀光中继放大的LED照明方法。该照明系统结构简洁、组装制造方便,同时又可以为显示芯片提供高效率的、高均匀度的、小角度的矩形光斑照明。论文的最后通过一款独立式CF-LCoS微型投影光引擎设计以及实际的样机制作与测试工作验证了该种基于光棒匀光中继放大的LED照明方法的有效性。论文研究工作的主要创新点有：(1)论文所有设计都是针对LED实际光线文件模型,而非理想光源模型；(2)重新认识了光学曲面角的作用,首次提出了一种基于光学曲面斜率角控制的非成像光学器件优化方法；(3)首次应用曲面斜率角控制优化方法成功设计了一款基于单片集光镜LED照明的嵌入式CF-LCoS微型投影光引擎,非常适用于手机等移动平台上的应用；(4)应用曲面斜率角控制优化方法对基于TIR透镜的光引擎照明系统,以及基于集光镜和柱面镜生成椭圆光斑的光引擎照明系统,二类照明方式进行优化设计,获得了光引擎光能利用率的提升；(5)利用数学推导对复眼和光棒二种匀光方式的共同点和差异点进行分析比较,首次提出了一种基于光棒匀光中继放大的LED照明方法；(6)通过基于LED照明的独立式CF-LCoS微型投影光引擎的设计以及实际的样机制作与测试验证了基于光棒匀光中继放大的LED照明方法的有效性,该款微型投影光引擎ANSI九点法输出40lm,均匀度达到94%,对比度超过180,同时样机的实测光能利用率达到了4.83%,可以满足一般的独立式微型投影显示的需求。更多还原

【Abstract】 A review of the role of the optical surface slope angle in optical system was first carried out by recalling the refraction/reflection process in the traditional imaging and non-imaging optics. No matter in imaging or non-imaging optics, the optical surface slope angle plays an import role, with which the ray convergence, ray divergence, and light energy redistribution are directly applied. Compared with the surface profile control based optimization method used in the traditional non-imaging optical element design, the surface slope angle control based optimization method was proposed for the first time. With the proposed method, three problems which lied in the traditional surface profile control based optimization method can be effectively overcome. One non-imaging reflector design example for general illumination was run in this thesis to verify the advantages by applying the surface slope angle control based optimization method.The surface slope angle control based optimization method was applied in thesis to design for the illumination system of pico-projection optical engine. First one CF-LCoS based optical engine for emendation was designed with LED rays collimated by single collection lens. This optical engine has a simple structure, a low cost, and is very suitable for assembly and production. The optical engine can also provide efficient light output and uniform projection light distribution. Thus it is very suitable for mass application in mobile platforms like cell phone. Besides applying the surface slope angle control based optimization for the TIR lens to achieve high light efficiency and compact size, the surface slope angle control based optimization was also applied to optimize for the elliptical illumination, which was generated by the combination of the collection lens and the cylinder lens. Though the elliptical illumination based optical engine takes a larger volume, it can provide a flux improvement of over 10% compared with the single collection lens based system. The most important advantage kept by the elliptical illumination is that it can provide the same light collection efficiency for display panels with free aspect ratio.Another research in this thesis is the design for white LED powered stand-by CF-LCoS optical engine. The mathematical derivation was first carried out to analyze the common points and difference between fly-eyes and light pipe based traditional uniform illumination systems. Both two methods acquires uniform irradiance by dividing and integrating the output ray spreading angle, but the light pipe based system has its unique "mirror integration" process, with which the light pipe based system can have the same performance by applying both odd and even symmetrical sources. By discovering the disadvantages which lies in these two traditional uniform illumination systems, one LED illumination method was proposed based on the light pipe based uniform illumination, and magnification lens based light transfer. The proposed illumination system has simple structure, and is suitable for assembly and production. It can also provide the display panel with a rectangular light spot that has a high light efficiency and a uniform light distribution with the small ray incident angle. By the applying sample production and test process for the stand-by CF-LCoS based optical engine, the new proposed LED illumination method can be found to be effective.The novel ideas introduced by this thesis are listed as follow:(1) All the designs in this thesis were based on LED real ray file model instead of the perfect model. (2) A review of the role of the optical surface slope angle was carried out, and the optical surface slope angle control based optimization method for non-imaging optical element was proposed. (3) By successfully applying the surface slope angle control based optimization method, one LED powered CF-LCoS based optical engine was designed with LED ray collimated accomplished only by single collection lens, and this optical engine was very suitable for applications in mobile platforms like cell-phone. (4) The surface slope angle control based optimization method was also applied to optimize for the TIR lens based illumination system and the elliptical illumination system generated by the combination of both collection lens and cylinder lens, and both light efficiency improvements had been acquired. (5) The mathematical derivation method was applied to discover the common points and difference between the fly-eyes and light pipe based uniform illumination system, and one novel LED illumination method was proposed based on the light pipe based uniform illumination, and magnification lens based light transfer. (6) By applying the design, sample production, and sample test process of the LED powered stand-by CF-LCoS optical engine, the new proposed LED illumination method can be verified to be an effective method. The stand-by optical engine can provide an ANSI 9-point output flux of 401m, an irradiance uniformity of 94%, and a contrast ratio of over 180. The light efficiency of the sample optical engine is about 4.83%. This optical engine can satisfy the general need of the stand-by pico-projection.更多还原