【作者】 王尚；

【导师】 刘胜；

【作者基本信息】 华中科技大学 ， 光电信息工程， 2012， 博士

【摘要】 随着大功率发光二级管(LED)芯片流明效率、封装集成度的提升和制造成本的下降,大功率LED越来越多的应用于各种照明领域。由于单颗LED芯片的总光通量有限,将多颗LED芯片以平面阵列的形式进行整体封装形成扩展光源模块来提高光源光通量已经成为LED封装的主流趋势。但另一方面,多LED芯片的集成封装会导致光源的发光面积增大,光源的近场区域不再可以视为点光源和Lambert型配光来进行处理,为LED的应用光学设计带来了巨大的难题。本论文围绕实现阵列式LED扩展光源的光束控制及其优化方法,进行了LED自由曲面光学设计与LED阵列优化的相关研究工作,提出了一系列新的自由曲面透镜算法与空间整体照明设计方法,并基于这些算法设计了各种新型自由曲面透镜,提高了LED光学系统的光效,实现了配光可控和光型可变换。研究内容主要包括小间距LED阵列自由曲面光学系统优化方法和大间距LED阵列的光学系统设计与阵列排布方式的自动优化方法等。针对小间距LED芯片阵列光源的照度分布优化,提出了一种基于网格调控理论来实现全出光角度可控的自由曲面透镜优化算法。该算法在等能量划分的基础上进行了能量映射优化,实现了对扩展光源的光型可控。在此方法的基础上,我们又提出了非对称形式的网格调控方法。该方法除上述方法的优点以外,能量映射关系更为灵活。基于两种方法我们设计的两款LED阵列式道路照明模块,具有较高的亮度、照度均匀性和较低的眩光值。针对小间距LED芯片阵列扩展光源的光强度分布优化,提出一种基于逆向拟合方法的自由曲面优化方法。该方法利用采集、反馈不同出射角度的光强度分布信息来反向优化透镜面型,使得扩展光源所造成的配光劣化得到补偿。利用该方法设计了正态分布形式的高光效、可调节地面导航光学系统,各项光学指标符合ICAO的相关要求。针对大间距LED光源阵列的优化排布,提出了两种基于区域补偿理论的均匀照明自动调节算法——区域扩展法和亚区域补偿法。此方法能够根据实际的光强度获得可用于模拟运算的光强度分布形式,通过对LED阵列的排布方式进行优化,可以改善照明均匀性。在实际应用中,实现利用较少的LED模块获得较高的照度均匀优化效果,案例均匀度达到了0.6以上。针对大间距LED阵列光源的自由曲面光学系统设计,我们提出了一种基于自由曲面结构阵列的扩展光源光束控制方法。在该方法的基础上,我们设计了能够实现一维扩束、圆形均匀照明、矩形均匀照明的光学系统,并提出了一种光型可变换的阵列结构光学系统。在微结构板的基础上提出了利用自由曲面算法对微结构光学薄膜的面型进行优化,使得光学薄膜实现光效增加、均匀照明和光型可控。同时我们研发了一款适用于舞台灯的多通道阵列式LED光源的调光控制系统,利用DMX512通讯协议控制单片机进行PWM调光最终实现8种颜色的256级调光,从而实现全彩照明。在色品图的颜色覆盖范围超过传统舞台灯的范围,能够生成更多的极端颜色照明。更多还原

【Abstract】 High power light-emitting diodes (LEDs), with increasing luminous efficiency and cost performance in recent years, have more and more applications in lighting. Due to small luminous flux of single LED chip, it is a tendency to use multi-chip package to enhance luminous flux. However, LED chip array will lead to large light-emitting area which can not be treated as point source. And this is a great difficulty for LED optical system design. To overcome the drawbacks of controllable radiation pattern (RP) and optimization method of LED array lighting, this dissertation mainly focuses on the research of freeform optics design and arrangement plan for LEDs array. Based on these methods, multifarious novel freefrom lens are designed to increase the optical efficiency and to form controllable beam pattern. Achievements are presented below.For the illuminance distribution of LED chips array with small spacing, we propose a novel freeform lens algorithm based on optimizing the division of target grids for uniform illumination, which provides the illuminance information and adjusts the energy mapping. Based on this method, we develop a non-symmetry optimization method. It has more flexible light energy mapping relationship than symmetry method. Based on these two methods, we design two novel road lighting modules with LED chip array source, which can provide both high illuminance/luminance uniformity and glare control.For the light intensity distribution of LED chip array with small spacing, we propose a circle-symmetry freeform lens algorithm based on reversing fitting design method for extended source, which collects and feeds back the light intensity distribution information and reversing optimize freeform surface of lens. It can quantificationally correct light intensity distribution error which are created by the extended source. As an example, aeronautical ground optical system is designed with this method, which can meet the requirements of ICAO very well.For the arrangement plan of LED array with large spacing, we propose two auto-optimization algorithms based on Illuminated area Expending and Sub-regions Compensating methodologies for uniform illumination, which input initial values of lamp and optimize arrangment of LED array. As an example, aeronautical ground optical system is designed with this method, which can meet the requirements of ICAO very well. In the practical application, we get a high uniformity of illumination distribution (0.6) with less LED modules.For the optical system design of LED array with large spacing, we propose a ray control method based on collimation and beam expender optical system for extended source, which uses micro-freefrom array lens or flim to control the collimated rays emitted from LED array. We can get a variety of radiation patterns by overlaying or removing lens. At the same time, we develop a milti-channel control system for LED stage lamp, which can form full variety colours. Its colour range is larger than the traditional lamps and more extreme colours can be created.更多还原