自由曲面前照灯近光配光的计算机仿真分析

汽车前照灯防眩日技术是影响汽车行驶安全的一个关键技术,同时,它又是一个目前尚未很好解决的世界难题。该文分析了自由曲面前照灯的发展背景,阐述,ECE法规对前照灯近光配光的要求,对光线追踪原理进行了理论探讨。利用ReflectorCAD软件反求出了自由曲面反光镜的三维模型,然后,通过TracePro软件建立线光源的仿真模型,对光线进行追踪,最终仿真出了自由曲面反光镜在25m外配光屏上的实际配光效果。     

车用LED照明技术及现状分析

随着汽车工业的快速发展,对汽车节能减排及安全性能的要求越来越高,汽车照明系统的节能与安全问题已成为该领域研究的热点.作为第四代车用光源,LED有很多优于其他传统光源的特点.为此分析了车用LED照明的可行性和先进性,介绍了其典型的驱动电路,并着重研究了LED以及AFS在汽车前照灯上应用现状.介绍了车用LED照明面临的问题及应对措施,并对其未来发展进行了展望.     

基于地球模拟器LED光源反光碗的设计

结合恒星模拟器的需要,使用LED光源,设计特定光强的照明系统。要求达到需要的光强分布。以此模拟色温为7000K的恒星,用于敏感器的标定。本文结合非成像光学理论,设计反光碗,对LED组进行配光整形,合成需要的配光曲线。使用4个LED光源芯片,反光碗口径为600mm。应用lighttools软件,建模仿真,得到仪器的配光曲线,与参考曲线进行对比,误差小于15%。     

提高汽车背景光大面积照明亮度一致性的光源布置

汽车背景光系统广泛应用LED光源进行照明,单颗LED近似为点光源,在较大面积照明的情况下,LED光源的布置方式在很大程度上影响了亮度的一致性.研究了LED作为背光源的照明特点,分析了LED背光源的布置对汽车背景光亮度一致性的影响,提出一种通过优化光源布置确定相邻LED间距提高汽车背景光较大面积照明亮度一致性的方法.该方...     

悬臂式灯具配光自动化测试设备研究与实现

为了实现摩托车前照灯光照度和信号灯发光强度的自动化测试,自主研发了一种悬臂式灯具配光性能测试设备.阐述了测试设备的工作原理和系统组成,设计开发了测试设备的机械结构、控制子系统、测试子系统、软件系统等主要模块,并以摩托车制动灯为例进行配光测试实例验证.研究表明,悬臂式配光测试设备可以实现摩托车前照灯和信号灯配光性能的高效自动化测试,具有较好的测量精度和稳定性;测试设备已投入生产使用,满足生产单位的测试需要.     

汽车自适应前照灯控制系统设计与验证

汽车自适应前照灯系统对于提高汽车在夜间和恶劣环境中的行车安全具有重要意义。该文通过分析研究汽车前照灯照明的作用与意义,建立了汽车自适应前照灯系统控制模型。在此基础上,设计了一种汽车自适应前照灯控制系统及其验证平台,从控制模型与控制精度两个方面予以评估论证,实验数据显示控制效果良好。     

汽车灯具配光性能测试系统

文中介绍的测试系统是用于汽车灯具检测的专用设备。它可以按照国家标准和国际ECE标准检验防眩目前照灯的配光性能及光型测试,可为改进车灯设计提供科学的依据。由于采用微机控制,因而它具有自动数据采集和数据处理等各种功能,除可定点或逐点测试外,还能描绘光型的等照度曲线。     

LED远场光强分布测试平台设计

提出并设计了以LED作为光源进行远场光强测试的平台,包括光路与电路两大部分,详细描述了远场测量的实现方法、光电转换与信号处理过程、电路设计原理.运用MATLAB进行数据处理,拟合出远场光强分布曲线,分析了距离、辐射角度与光源强度的关系.经测试,在远场空间某一定点的光强值只与光源强度相关,在辐射角内可以直接体现光源稳定性.     

光纤耦合紫外LED光源及其在水质检测中的应用

本文介绍了光纤耦合LED光源的组成结构,结合应用需求设计制作了一款光纤耦合紫外LED光源并给出了LED的驱动电路。利用该光源搭建了荧光检测实验平台,针对水中铅离子的检测进行了实验研究。     

投影仪的LED光源驱动器的设计

介绍了在采用LED做光源的投影仪中,如何设计LED光源的驱动电路.分析了负压型Buck电路的设计及PWM调光电路、短路保护、过压保护、环路测试等问题.     

Fast Inverse Reflector Design (FIRD)

This paper presents a new inverse reflector design method using a GPU‐based computation of outgoing light distribution from reflectors. We propose a fast method to obtain the outgoing light distribution of a parametrized reflector, and then compare it with the desired illumination. The new method works completely in the GPU. We trace millions of rays using a hierarchical height‐field representation of the reflector. Multiple reflections are taken into account. The parameters that define the reflector shape are optimized in an iterative procedure in order for the resulting light distribution to be as close as possible to the desired, user‐provided one. We show that our method can calculate reflector lighting at least one order of magnitude faster than previous methods, even with millions of rays, complex geometries and light sources.     

Gradually tapered light pipes for illumination of LED projectors

Abstract— LEDs are totally different from classical light sources: they have a different shape, radiation pattern, driving requirements, etc. Therefore, the illumination engine, which determines the brightness and uniformity of the system, has to be redesigned for LED‐based projectors. A compact illumination system based on gradually tapered light pipes (GTLP) will be presented. The GTLP collects, reshapes, and uniformizes the light flux from the LED to illuminate the light‐valve uniformly. The design and the simulations have been completed. The result is a uniformly illuminated rectangular beam at the end of the pipe with an efficiency of 81.1%. Afterwards, the light pipe was fabricated, and the experimentally measured efficiency is 76.9%, which demonstrates a successful manufacturing process. Finally, two recycling techniques to enhance the brightness have been applied and these enhancements were experimentally observed.     

LED照明产品的情感化设计

随着LED照明产品日渐普及的今天,设计此类产品所要关注的不仅是技术和外观方面等因素,更需要情感化的设计去实现人们内心的丰富需求。本文从LED照明产品中所涉及的外形、色彩、材质及功能的情感化设计进行探讨,藉此分析并且展望当今和未来的LED照明产品将如何构建出人、光、物(产品)之间的和谐关系。     

Applying genetic programming and ant colony optimisation to improve the geometric design of a reflector

The lighting performance of an LED (light-emitting diode) flash is significantly influenced by the geometric form of a reflector. Previously, design engineers have usually determined the geometric design of a reflector according to the principles of optics and their own experience. Some real reflectors have then been created to verify the feasibility and performance of a certain geometric design. This, however, is a costly and time-consuming procedure. Furthermore, the geometric design of a reflector cannot be proven to be actually optimal. This study proposes a systematic approach based on genetic programming (GP) and ant colony optimisation (ACO), called the GP–ACO procedure, to improve the geometric design of a reflector. A case study is used to demonstrate the feasibility and effectiveness of the proposed optimisation procedure. The results show that all the crucial quality characteristics of an LED flash fulfil the required specifications; thus, the optimal geometric parameter settings of the reflector obtained can be directly applied to mass production. Consequently, the proposed GP–ACO procedure can be considered an effective method for resolving general multi-response parameter design problems.     

HB-LED医用手术头灯控制系统的设计与实现

研制了以高亮度LED为光源的医用手术头灯控制系统。该系统由电源路径管理电路、充电管理电路、LED驱动电路和调光电路组成。采用外部电源或者电池双电源供电,可驱动5W的大功率白光LED,同时具备LED亮度连续调节和电池充电管理等功能。LED亮度调节实验和锂电池充电实验表明该控制电路很好地符合了预期的设计要求,LED控制电路具有很强的通用性,体积小、价格低廉,适合于便携式电子产品的设计应用。     

基于无线网络控制的智能照明系统

根据节能环保、智能家居的需求,采用LED灯和TI的SoC芯片CC2431设计了一套基于ZigBee无线网络控制的智能照明系统。该系统可在兼容已有调光模式的基础上,利用照度值来精细调节局部照度,从而实现简单的照明定位控制。文中详细阐述了系统各个模块的软硬件设计方法。经实际室内测试表明:该系统性能良好,操控简便,而且更加人性化。     

恒照度调光的LED驱动器设计

随着照明技术的不断发展以及能源的日益紧张,绿色照明成为主要的研究方向。本文针对传统照明能效低、耗电量大等问题,设计了LED恒照度调光驱动器。系统使用恒流LED控制芯片NCL30160作为LED光源驱动电路,采用TSL2561光照度传感器采集室内光照度,通过处理器相应算法进行闭环控制,实现室内的恒照度调光。该算法实现了PWM波形平滑变化,避免因PWM突变造成闪光。同时,系统增加了人体运动控制,实现无人、有人时的不同调光方案,使设计进一步节能和智能化。     

Novel heat dissipation design for light emitting diode applications

The authors offer a new design in support of efficient heat dissipation for light emitting diodes (LEDs). In the first part of this paper we discuss improvements in LED packaging materials and layer assembly, and then describe the addition of a thin layer of electroplated copper to the LED base assembly to reduce thermal resistance and increase thermal diffusion efficiency. Also described is a three-dimensional finite element simulation that we performed to verify the proposed design (0.75, 1, and 3 W LED chip temperatures) and a LED heat transfer behavior analysis. The results indicate that the addition of a 9 mm² electroplated copper layer to the LED base assembly improved LED thermal dissipation by reducing chip temperature by 5°C compared to LEDs without the copper layer packaging. In the second part of this paper we describe (a) our heat pipe system/heat sink design for LED illumination, and (b) experiments in which we changed both working fluid mass and rotation angle to determine their effects on heat pipe cooling. Our results indicate that the most efficient heat dissipation occurred when an added heat pipe was arranged horizontally. Good heat dissipation was observed for heat pipes containing 2.52 g of water (temperature reduced by 50°C). Larger water volumes failed to dissipate additional heat due to the presence of steam inside the pipe.     

Integration of stamper fabrication and design optimization of LCD Light guides using silicon-based microfeatures

This study applies a novel fabrication process that combines anisotropic wet etching of silicon-on-insulator (SOI) wafers with electroforming to manufacture precision stampers. Micron-sized features, such as trapezoidal grooves and truncated pyramidal prisms, can be fabricated and distributed accurately. Because feature geometry and distribution can be accurately realized using the proposed scheme, design optimization of light guide plates (LGPs) becomes realistic. By observing the illumination characteristics of light emitting diode (LED) edge-lit LGPs, the distribution pattern of the LGP is transformed into a parameter design with seven anchor spacing and the spacing modulation amplitude of the micro features adjacent to LEDs. The proposed fuzzy optimization scheme manipulates distribution parameters to obtain an LGP design with high illumination uniformity. The design of a 3.5-inch LED edge-lit LGP is used as an illustrative example. The optical software program TracePro is applied to simulate luminance performance of BLM. The optimization converges rapidly and provides the optimum design with an average brightness of 2,266 (nit) and uniformity of 90% without use of diffusive sheets. Thus work demonstrates the feasibility and effectiveness of the proposed scheme.     

手指静脉识别传感器的光源设计

针对手指静脉图像采集系统中近红外LED光源的光强均匀性相对较差的问题,设计了一种等边三角形结构的光源阵列.通过应用近红外LED光源的数学模型和斯派罗法则优化两个相邻光源的距离,确定了两颗光源之间的最优距离为6.26 mm,对该光源阵列进行仿真形成面积为10 mm ×20 mm的均匀光照区域.对此光源阵列进行硬件实验,证明等边三角形结构的光源阵列比单排的光源阵列在均匀性和图像质量上更加突出.