应用于Mini‑LED背光的双自由曲面透镜设计  

Double Freeform Surface Lens Design for Mini-LED Backlight

作　　者：冯奇斌[1] 杨玲 张乐 靳鹏 王梓 吕国强[2] Feng Qibin;Yang Ling;Zhang Le;Jin Peng;Wang Zi;LüGuoqiang(Special Display and Imaging Technology Innovation Center of Anhui Province,National Engineering Laboratory of Special Display Technology,Academy of Photoelectric Technology,Hefei University of Technology,Hefei 230009,Anhui,China;School of Instrument Science and Opto-Electronics Engineering,Hefei University of Technology,Hefei 230009,Anhui,China;Anhui Coreach Technology Co.Ltd.,Hefei 230601,Anhui,China)

机构地区：[1]合肥工业大学特种显示与成像技术安徽省技术创新中心,特种显示技术国家工程实验室,光电技术研究院,安徽合肥230009 [2]合肥工业大学仪器科学与光电工程学院,安徽合肥230009 [3]安徽芯瑞达科技股份有限公司,安徽合肥230601

出　　处：《光学学报》2023年第8期346-356,共11页Acta Optica Sinica

基　　金：安徽省科技重大专项(202103a05020028)。

摘　　要：提出了一种单个透镜目标面照度分布的设计方法,根据背光中Mini-LED光源数量及阵列排布间距、混光距离、目标面光斑半径等信息,建立了背光目标面上照度值与单颗透镜目标面照度分布之间的映射矩阵,通过LSQLIN迭代优化算法得到单颗透镜目标面照度分布,最后采用光源-目标面能量映射法设计双自由曲面透镜。以Mini-LED阵列排布间距为39 mm×30 mm、混光距离为6 mm且目标面光斑半径为40 mm为例进行设计。仿真结果表明,所设计的透镜阵列应用于光源数为5×5的Mini-LED背光时,目标面照度均匀性达到87.45%,对比常用的均匀分布及高斯分布分别提升6.24%和3.34%。本方法在确保背光照度均匀性的前提下降低了透镜设计的计算复杂度,无需大量的后续优化工作,为Mini-LED背光中双自由曲面透镜的设计提供了一种实用有效的方法。Objective Liquid crystal displays(LCDs)have been widely employed in various applications,keeping moving towards thinner thickness and lower power consumption.As liquid crystal does not emit light,backlight modules are required to provide illumination rays.Mini light-emitting diodes(Mini-LEDs)have been considered promising light sources for ultrathin direct-lit backlight modules.In the backlight module,double freeform surface lenses are usually employed to redistribute rays emitted by the chip and further reduce the optical distance(OD),further reducing the backlight module thickness.The common design of the lens is based on a point light source with the rays regulated by the lens to form a spot on the target plane and multiple spots superimposed to form the surface light source on the target plane of the Mini-LED backlight module.Therefore,the illuminance distribution of a single lens on the target plane is very important for the illuminance uniformity of the backlight module.Usually,the illuminance distribution of the target plane is directly set to uniform distribution or Gaussian distribution.However,in previous methods and algorithms,the simultaneous deterioration effects related to the number of Mini-LED chips,the distance between two adjacent lenses,and the optical distance have been ignored at the same time.The illuminance uniformity of the backlight module adopting the traditional method decreases,which causes troubles to the practical application.Therefore,it is necessary to reasonably design the illuminance value of the target plane based on a given array configuration and array pitches for ensuring the uniform illuminance distribution of the backlight module on a certain OD.Methods This paper proposes a design method to achieve uniform illumination with a high distance-height ratio(DHR).The principle of the method can obtain the illuminance distribution of a single lens on the target plane.The design is carried out in a backlight module with a Mini-LED number of P×Q and an array ofΔpitch,x×Δpitch,y

关 键 词：光学设计 背光模组 双自由曲面透镜 目标面照度分布 迭代优化算法 

分 类 号：TN141.9[电子电信—物理电子学]