改进宽银幕投影显示照明系统的设计方法

照明系统是投影显示系统的重要组成部分,决定着整个系统的亮度和照明均匀性。复眼系统是一种常见的液晶投影显示系统照明结构。传统的复眼照明系统设计方法中,复眼小透镜具有与液晶板相同的长宽比,可以获得能量利用率和均匀性都比较好的照明光斑。但研究发现,利用这种方法设计宽银幕投影显示设备的复眼照明系统,会引起一定的光能损失。针对这一问题,通过对复眼系统设计理论的分析和对实际复眼照明系统的模拟,创新性地提出了在照明系统中引入柱面透镜改变复眼小透镜的长宽比的设计方法,能够有效的提高投影系统能量利用率。模拟计算结果表明,引入柱面透镜的复眼照明系统与传统方法设计的复眼系统相比,能量利用率可以提高5％到10％。     

液晶投影显示复眼照明的容差模拟分析

介绍了液晶投影显示复眼照明的工作原理,采用扩展4×4矩阵模型描述了复眼照明,以能量利用率和照明均匀性作为系统的评价标准,对复眼透镜的制造误差和位置误差进行计算机模拟分析,分析表明,双排复眼透镜相对位置误差对系统性能影响大于加工误差,而第一排复眼透镜的加工误差对能量利用率的影响大于第二排复眼透镜,第二排复眼透镜的加工误差对照明均匀性的影响大于第一排复眼透镜.     

一种应用于LCoS光机的复眼照明系统仿真设计

复眼照明系统利用复眼透镜，可实现高亮度和较好的亮度均匀性，并且有较成熟的偏振处理方法，在投影系统特别是基于偏振光的投影系统中能提供比光棒照明系统更加高的亮度和好的均匀性的画面，使得光能利用率和图像均匀性有了较大的提高。在对复眼照明系统的原理进行分析的基础上，设计了一种用于投影光机的复眼照明系统，并用Matlab对该系统进行了光线追迹的仿真程序设计。对复眼照明系统的光线追迹进行了仿真。实际应用证明，在LCoS中采用本方案设计的照明系统比光棒照明系统具有更高的亮度和更好的均匀性。     

辐射与发光 光源与照明光学

TM923．3 2005020853 液晶投影显示复眼照明的容差模拟分析=Tolerance anal— ysis on fly’s eye illumination system of LCLV projector [刊,中]／郑臻荣(浙江大学现代光学仪器国家重点实验 室．浙江,杭州(310027))//光子学报.-2004,33(5).- 593—597 介绍了液晶投影显示复限照明的工作原理,采用扩展 4×4矩阵模型描述了复眼照明,以能量利用率和照明均匀 性作为系统的评价标准,对复跟透镜的制造误差和位置误     

用于LED照明的反射型复眼设计方法

设计了一个高亮度LED光源照明的反射型复眼照明系统.通过软件模拟,整个复眼系统长度小于20 mm,物面的光照均匀度达到80％以上,光源照明输出光能利用率为75％.应用高亮度LED的反射型复眼具有体积小,光强分布均匀,像差小等特点.在小型便携式投影仪中有广阔的应用前景.     

激光显示照明光路中复眼透镜的设计

设计激光投影机光学系统需要从如何减小光学系统的体积和提高激光光源的光效两个方面考虑。研究了激光显示照明系统中的复眼透镜,并对设计的复眼小透镜矩形单元进行了优化,发现在复眼透镜整体尺寸和单颗复眼小透镜焦距一定的情况下,整个复眼透镜上的阵列越多,即复眼透镜上蜂窝的数量越多,其匀光效果就越好,且此时投影机系统的体积也较小。为了提高激光光源的光效,设计中对复眼透镜在不同数值孔径照明光束下的匀光效果进行了讨论。并对优化设计后的复眼透镜进行40 000条光线追迹,实验显示其光线透过率可以达到92.5%,且几乎无杂散光。     

用于CF-LCoS LED照明的大角度复眼系统共轭成像优化设计

根据LED发光特性以及彩色滤光片式硅基液晶芯片特性,从成像光学的角度导出了复眼照明系统的基本成像公式.在此基础上由彩色滤光片式硅基液晶芯片目标区域的大小及其对光束入射角以及LED经整形以后的光斑尺寸与发散角的要求,根据推导的复眼系统的基本成像公式计算彩色滤光片式硅基液晶芯片复眼照明系统的初始结构,利用复眼照明系统中的多重共轭成像关系,将复眼成像,中继透镜成像分别优化,最后将两者通过孔径与中间像匹配的基本要求进行复眼阵列组合,设计了基于彩色滤光片式硅基液晶芯片的大照度入射光下的复眼照明系统.该系统以较小的复眼数,在保证彩色滤光片式硅基液晶芯片照明要求的条件下,较好地解决了照明系统效率、均匀性与大角度问题.与传统计算方法相比,该方法简单明了.非成像软件的模拟结果证明该方法准确,均匀性好,效率高.实验样机结果验证了本文所提方法的正确性和有效性.     

辐射与发光 光源与照明光学

TM923．01 2005031431 改进宽银幕投影照明系统的设计方法=Method for impro- ving the performance of wide screen projection display illu- mination system[刊,中]／周杰(浙江大学现代光学仪器国 家重点实验室．浙江,杭州(310027)),林宇翔…∥光学学 报．-2005,25(2)．-224-227 传统的复眼照明系统设计方法中,复眼小透镜具有与 液晶板相同的长宽比,可以获得能量利用率和均匀性都比     

基于复眼透镜的大面积均匀照明方案研究

为了实现大面积矩形均匀光斑,提出一种基于双排复眼透镜的设计方案。使用TracePro软件对该照明系统方案的效果进行建模仿真,分析了复眼透镜组的间距、后工作距离等参数对光斑面积和均匀性的影响。结果表明,复眼透镜间距越小、后工作距离越大,得到的光斑面积越大;而当间距控制在微透镜焦距附近时,光斑均匀性最佳。利用该设计方案,可在1 m的后工作距离得到尺寸350 mm200 mm的光斑,光斑中心280 mm160 mm范围内光照度均匀性＞0.85,该部分面积超过光斑整体面积的60%。该匀光方案有望在医用光疗、路灯照明等大面积均匀光照明领域得到广泛应用。     

基于微透镜阵列的DMD芯片投影系统照明优化

分析了照明系统中微透镜阵列的入射光线角度及系统像差对光学利用率的影响,提出了通过修正相关参数来优化照明系统的光学利用率以及照明均匀性的方法。通过改变用于光源聚光的自由曲面透镜的面型来缩小入射角度,从而减小了由于大角度扩散造成的效率损失。并且在微透镜阵列后采用两个球面透镜代替傅里叶透镜作为积分镜片,不仅成本低廉,而且在控制像差方面更为灵活。参数优化后,设计方案的光学利用率可达60.51%,均匀性可达94.24%,验证了理论分析的可行性和有效性。     

Design of artificial apposition compound eye with cylindrical micro-doublets

We present the design of a non-conventional optical system that uses cylindrical micro-doublets (CMD), integrated in an artificial apposition compound eye configuration (AACE). We show some designs of an ultra-thin objective inspired in fly eyes. These designs can give options to create new technologies that will process information in a different and effective way as usual. This process will be carried out by means of sampling the object with an array of multiple micro lenses using a certain value of the acceptance angle, and processing the optical signal to obtain partial images that will be part of a global one. The objective has the advantage of having a smaller size, a wider field of view, and an acceptable image quality compared with some conventional systems. Design parameters of the AACE and optical performance of the CMD are reported.     

基于硅基液晶显示技术的可见光光学目标模拟器的研制

为了产生制导武器仿真系统中所需的逼真的目标背景图像,建立了基于硅基液晶显示技术的可见光光学目标模拟器。给出了模拟器图像输出的实际效果图以及光学参量的测试方法和数据。测试表明,该装置有较好的亮度、对比度和均匀性,与传统的阴极射线管显示技术相比有效减轻了图像闪烁问题,能够提供稳定的视频输出,更有利于仿真系统中对动态目标的识别,是一种较为理想的图像模拟装置。同时给出了双复眼光学系统初始结构的计算方法并推导出简单的计算公式,该算法可以应用于其他双复眼照明系统中。     

基于自由曲面透镜的三基色LED照明系统研究

基于三基色发光二极管(light emitting diode，LED)与方棒的投影照明系统具有色域宽、体积小的优点，但三基色LED和方棒配合使用时，存在投影亮度不高的问题。首先基于光学扩展量匹配原则选择了LED光源，然后设计了一组自由曲面的准直透镜和收集透镜。仿真结果表明:准直透镜出射光线集中在±7.5°内，方棒出射端±30°内的能量利用率为51.7%。实际加工并测试了设计的自由曲面准直透镜和收集透镜。测试结果表明:采用本文设计的没有镀减反增透膜的透镜组，投影机出射亮度比原使用镀了增透减反膜的透镜的系统高1.6%。预计设计的透镜镀减反增透膜后投影机出射亮度有望提升9.8%。     

Binocular adaptive optics vision analyzer with full control over the complex pupil functions

We present a binocular adaptive optics vision analyzer fully capable of controlling both amplitude and phase of the two complex pupil functions in each eye of the subject. A special feature of the instrument is its comparatively simple setup. A single reflective liquid crystal on silicon spatial light modulator working in pure phase modulation generates the phase profiles for both pupils simultaneously. In addition, another liquid crystal spatial light modulator working in transmission operates in pure intensity modulation to produce a large variety of pupil masks for each eye. Subjects perform visual tasks through any predefined variations of the complex pupil function for both eyes. As an example of the system efficiency, we recorded images of the stimuli through the system as they were projected at the subject's retina. This instrument proves to be extremely versatile for designing and testing novel ophthalmic elements and simulating visual outcomes, as well as for further research of binocular vision.     

SLM-based maskless lithography for TFT-LCD

Maskless photolithographic methods have been developed using digital micromirror devices (DMDs) and grating light valves (GLVs), which are spatial light modulators (SLMs), because liquid crystal display (LCD) panel industries spend huge amounts of money for the cost of TFT (thin film resist)-LCD photomasks. The technology has been developed for implementing 2 μm bitmap resolutions, which is a requirement for the lithographic process, though the process time is still slow for mass-production system. A DMD-based maskless exposure uses 405 nm-wavelength semiconductor lasers as an illumination source and optical engines that contain DMDs, micro lens arrays (MLAs), and projection lenses. A GLV-based system consists of UV lasers and optical write engines, which are constructed with the GLV, grating optics, and imaging lenses. Since many companies have been trying to overcome the time limitations, the maskless technology will be realized in the LCD industry in near future.     

Design of “Eye Closure” system for the stealth of photo-electric equipments

Based on the optical activity of liquid crystal, a new approach for the stealth of “cat’s eye” targets is proposed in this paper. It imitates the physiological close reaction of human eyes when strong light irradiates eyes. With this approach, the “cat’s eye” effect will vanish, which is applied in restricting photo-electric equipments being detected and located by active laser detection system. The structure and working principle of the design are presented. The drive circuit is given to control the optical switch automatically. Feasibility of this design is demonstrated by experimental method. The measured data illustrate that the proposed approach is effective to eliminate the “cat’s eye” effect, so as to enhancing the viability of photo-electric equipments on the battlefield.     

Adaptive optics fundus camera using a liquid crystal phase modulator

We have developed an adaptive optics (AO) fundus camera to obtain high resolution retinal images of eyes. We use a liquid crystal phase modulator to compensate the aberrations of the eye for better resolution and better contrast in the images. The liquid crystal phase modulator has a wider dynamic range to compensate aberrations than most mechanical deformable mirrors and its linear phase generation makes it easy to follow eye movements. The wavefront aberration was measured in real time with a sampling rate of 10 Hz and the closed loop system was operated at around 2 Hz. We developed software tools to align consecutively obtained images. From our experiments with three eyes, the aberrations of normal eyes were reduced to less than 0.1 μm (RMS) in less than three seconds by the liquid crystal phase modulator. We confirmed that this method was adequate for measuring eyes with large aberrations including keratoconic eyes. Finally, using the liquid crystal phase modulator, high resolution images of retinas could be obtained.     

New system for making stereoscopic holograms

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