X-ray backlighting of two-wire Z-pinch plasma using X-pinch

Two 50-μm Mo wires in parallel used as a Z-pinch load are electrically exploded with a pulsed current rising to 275 kA in 125 ns and their explosion processes are backlighted using an X-pinch as an x-ray source. The backlighting images show clearly the processes similar to those occurring in the initial stages of a cylindrical wire-array Z-pinch, including the electric explosion of single wires characterised by the dense wire cores surrounded by a low-density coronal plasma, the expansion of the exploding wire, the sausage instability （m = 0） in the coronal plasma around each wire, the motion of the coronal plasma as well as the wire core toward the current centroid, the formation of the precursor plasma column with a twist structure something like that of higher mode instability, especially the kink instability （m = 1）.

Parameters Optimization and Energy-Saving of Highway Tunnel Backlighting with LED

In order to acquire the most energy-saving luminairedistribution-parameters(LDPs)of highway tunnel interior zone backlighting,the parameters optimization model(POM)of backlighting for tunnel interior zone was established.Yanlieshan tunnel of Jiujing highway was taken as an example for the optimization.The optimal LDPs of the backlighting system of the tunnel interior zone were obtained by the POM,a comparison between the optimization results and those of Yanlieshan tunnel’s actual lighting system was performed,which showed that the optimized backlighting system with LED lamps installed according to the optimized LDPs could save energy remarkablely even under full capacity lighting condition.Illuminance and illuminance uniformity of the tunnel road surface still met the lighting demands even the LED lamp’s luminance decreased by 30%.A backlighting simulation experiment with the optimized backlighting LDPs for Yanlieshan tunnel was accomplished in the software Dialux.The simulation results basically agreed with the optimization calculated results from the POM which proved the correctness of the backlighting POM.

Wide color gamut switchable autostereoscopic 3D display based on directional quantum-dot backlight

A switchable autostereoscopic 3-dimensional(3D) display device with wide color gamut is introduced in this paper. In conjunction with a novel directional quantum-dot(QD) backlight, the precise scanning control strategy, and the eye-tracking system, this spatial-sequential solution enables our autostereoscopic display to combine all the advantages of full resolution,wide color gamut, low crosstalk, and switchable 2D/3D. And also, we fabricated an autostereoscopic display prototype and demonstrated its performances effectively. The results indicate that our system can both break the limitation of viewing position and provide high-quality 3D images. We present two working modes in this system. In the spatial-sequential mode,the crosstalk is about 6%. In the time-multiplexed mode, the viewer should wear auxiliary and the crosstalk is about 1%,just next to that of a commercial 3D display(BENQ XL2707-B and View Sonic VX2268 WM). Additionally, our system is also completely compatible with active shutter glasses and its 3D resolution is same as its 2D resolution. Because of the excellent properties of the QD material, the color gamut can be widely extended to 77.98% according to the ITU-R recommendation BT.2020(Rec.2020).

End-on x-ray backlighting experiments for axial diagnostics of wire-array Z-pinch plasma on PPG-1

An X-pinch axial backlighting system has been designed to quantitatively measure the density distribution of wirearray Z-pinch plasmas. End-on backlighting experiments were carried out on a 200 kA, 100 ns pulsed-power generator（PPG-1） at the Tsinghua University. Compared with side-on backlighting, end-on measurements provide an axial view of the evolution of Z-pinch plasmas. Early stages of 2-, 4-, and 8-wire Z-pinch plasmas were observed via point-projection backlighting radiography with a relatively high success rate. The density distribution of Z-pinch plasma on the r–θ plane was obtained directly from the images with the help of step wedges, and the inward radial velocity was calculated. The ablation rates obtained by X-pinch backlighting experiments are compared in detail with those calculated by the rocket model and the results show consistency.

Optical Microstructure Design Optimization for Display Backlighting

This study proposes an innovative design method for functional optical film microstructures used in displays and applies this design to LCD backlighting to replace multi-layer optical film functional integration with composite optical film. We design a novel optical film microstructure based on light uniformity and wide-angle lumination distribution and determine the optimal optical microstructure parameters by combining the global optimization of a genetic algorithm with ray tracing. The purpose of this study is to develop substitutes for traditional multi-layer prism brightness enhancers and light-diffusing film stacks and to examine the structural changes during calculations and summarize the characteristics. In this study, we focus on determining the optimal light uniformity of new optical film microstructures. The seven-inch LED backlight module of the method proposed in this study achieved 94.59% uniformity and 168° lumination distribution while reducing thickness by 66% to 82% compared to a traditional multi-layer optical film stack.

“逆境”之中显身手——巧用Backlight

在我们使用家用摄像机拍摄影像的时候可能通常使用的是程序自动曝光模式。这样可以免去调整焦距和调整光圈的麻烦,在很多的情形下,程序自动曝光模式工作得很好,我们拍出的影片令自己非常满意。但你是否遇到过这样的情况:拍摄的对象处于很亮的背景前面,或者被摄物前面部照明严重不足,也就是通常所说的逆光拍摄。这时,使用自动模式拍出来的效果就不尽人意了。画面背景显得比较亮,但却不会过度曝光,相映之下,被拍摄的主体则显得很暗,前面部细节无法很好的体现出来。这时,我们就要用到大多数家用摄像机都提供的一项功能:逆光拍摄(BackLight)。

Design of 25-inch Direct Illumination-type LED Backlight

We utilized "direct illumination-type" LED backlight project, made white-light LED array in rectangle, designed a sheet of reflective film, a sheet of diffuser and two sheets of brightness enhancement film, then analyzed illuminance chart which was the result of simulation in several distance between reflective film and optical film. It showed the best matching between illuminance and uniformity while in 25mm distance. Finally, we discussed some problems with thermal dispersion.

[(CH_(3))_(4)N]_(2)Mn_(0.6)Zn_(0.4)Br_(4):Lead-free MnII-based hybrid halide with high photoluminescence quantum yield for backlight displays

High efficient lead halide perovskites with wide-color gamut properties have emerged as new candidates for backlight displays.However,the toxicity of lead and the instability of halide perovskites greatly limit their practical applications.Herein,the luminescent powders of[(CH_(3))4N]2MnBr_(4)and[(CH_(3))4N]MnBr3 were synthesized via a simple yet robust solvent evaporation method.[(CH_(3))4N]2MnBr_(4)with tetrahedral coordination Mn^(2+)and[(CH_(3))4N]MnBr3 with octahedral coordination Mn^(2+)show green at 517 nm and red emission peaks at 620 nm,respectively,originating from the^(4)T1-^(6)A_(1)transition of Mn^(2+).To enhance optical of manganese halide via effective alloying,Zn^(2+)-doped[(CH_(3))4N]2MnBr_(4)was successfully prepared,and the quantum efficiency of[(CH_(3))_(4)N]_(2)Mn_(0.6)Zn_(0.4)Br_(4)was as high as 65%.Furthermore,[(CH_(3))4N]2Mn0.6Zn0.4Br_(4)exhibits better optical and thermal stability compared to[(CH_(3))4N]2MnBr_(4).[(CH_(3))_(4)N]_(2)Mn_(0.6)Zn_(0.4)Br_(4)@CsPbBr_(1.2)I_(1.8)light conversion films with different green-to-red ratios are placed in backlight display devices,and their color gamut exceeds 106%of the National Television Standards Committee(NTSC)1953 standard,which is superior to the currently reported Mn-based perovskite.This work broadly shows that the[(CH_(3))_(4)N]_(2)Mn_(0.6)Zn_(0.4)Br_(4)will provide effective route to fabricate stable and high-performance lead-free liquid crystal displays.

基于前背景特性的逆光交通场景图像增强

由于逆光交通场景下采集到的图像存在前景亮度过低、背景亮度失真等特点,导致采集图像清晰度低、信息丢失严重和可识别性差,针对逆光图像前背景的不同特性,研究提出了一种分区域增强方法。对逆光图像使用最大类间方差法(OTSU法)分割图像的前景和背景;对逆光图像全局使用LIME方法,提升前景亮度的同时保持色彩的失真度;单独将背景部分RGB三个通道上的全局直方图均衡化结果一一映射到对应的限定区间内,提高了背景的对比度;使用Canny算子检测出前背景拼接处的黑边,根据黑边生成3个自适应的滤波模板对黑边进行分步均值滤波处理,消除了黑色边缘,提升了图像的视觉质量。在实验室自建的CHD_B数据集上,所提方法在4种常用客观评价指标上综合占优。实验结果表明,所提出的图像增强算法能有效地消除图像中的逆光现象。

液晶汽车仪表LED背光硬件电路分析与设计

为了使液晶汽车仪表的背光灯在受到外界电气干扰的情况下能够保持稳定的输出电流、亮度不发生变化,对已使用的三种汽车仪表LED背光电路进行了研究和分析,提出了一种稳定性较高的硬件电路设计——仪表LED恒流源电路。该电路可通过调节精密电阻值来调节LED背光灯的亮度,设计方案简单、调整电流便捷、成本较低,在液晶汽车仪表市场中具有较高的应用价值。

基于区域调光算法的车载液晶显示技术研究及应用

为了提升传统车载液晶显示器的能效和显示质量,提出一种应用于车载液晶显示器的区域调光算法。将输入的RGB色彩模式转换为YUV色彩模式以提取像素点亮度数据,并依照背光分区对应的图像子区域提取亮度数据。采用分区背光模糊-扩散模拟LED背光源在背光模组中传播时的扩散过程,得到各像素点的背光亮度数据,并据此通过液晶像素进行精确补偿得到最终调光图像。仿真结果显示,该方法在图像信息熵、图像细节增强和峰值信噪比3个评价方法上,优于其他区域调光算法的增强效果。同时在样机实验中,平均整体能耗降低了20.7%。表明该算法能够在提高显示质量的同时合理降低车载显示器的整机功耗,对各类车载显示器都具有良好的适用性。

Green and red phosphor for LED backlight in wide color gamut LCD

Wide color gamut(WCG) backlight for liquid crystal display(LCD) utilizing white light-emitting diodes(LED) has attracted considerable attention for their high efficiency and color reduction.In this review,recent developments in crystal structure,luminescence and applications of phosphors for wide color gamut LED backlight are introduced.As novel red phosphors,Mn4+activate fluoride and aluminate phosphors are advanced in quantum efficiency,thermal quenching and color saturation for their characteristic spectrum with broad excitation band and linear emission.The crystal structure and fluorescence properties of Mn4+doped fluosilicate,fluorogermanate,fluotitanate,as well as Sr4 Al14O25,CaAl12O19 and BaMgAl10O17 phosphors are discussed in detail.A serial of narrow-band red-emitting Eu2+,Eu3+and Pr3+-doped nitride silicates and molybdate phosphors are also introduced.Rare-earth-doped oxynitride and silicate green-emitting phosphors have attracted more and more attention because of the wide excitation,narrow emission,high quenching temperature,high quantum efficiency,such as β-sialon:Eu2+,Ba3Si6O12N2:Eu2+,MSi2O2N2:Eu2+(M=Ca,Sr,Ba),y-AlON:Mn2+and Ca3Sc2Si3O12:Ce3+.All above phosphors demonstrate their adaptability in wide color gamut LCD display.Especially for Mn4+doped fluosilicate red phosphor and β-sialon:Eu2+green phosphor.To achieve an ultra-high color gamut in white LED backlight and against the OLED,innovative narrow-band-emission red and green phosphor materials with independent intellectual property rights are continuously pursed.

ZnO induced self-crystallization of CsPb(Br/I)_(3) nanocrystal glasses with improved stability for backlight display application

In the current situation of energy shortages,saving energy and reducing consumption are undoubtedly valid methods to relieve the pressure on resources.CsPbX_(3)(X=Cl,Br,and I)perovskites as star inorganic materials have drawn growing attention owing to their unique properties,making them suitable for applications such as light-emitting diodes(LEDs),solar cells,photodetectors,or lasers.This work presents zinc oxide(ZnO)induced self-crystallized CsPb(Br/I)_(3) perovskite with a 26%photoluminescence quantum yield(PLQY)prepared by the traditional melt-quenching method.Furthermore,the full width at half maximum(FWHM)(34–44 nm)can be regulated by the ZnO content.In addition,as a downconverter,CsPb(Br/I)_(3) perovskite nanocrystals(NCs)realize a bright red backlight that covers≈94%Rec.2020 standards in the CIE 1931 color space and 126%of National Television System Committee(NTSC).This finding undoubtedly confirms an effective path for fabricating perovskite materials in a green,low-cost,and time-saving way,enriching the knowledge of glass crystallization mechanisms and promoting their applications in wide color gamut backlights.

Micro-projection dynamic backlight for multi-view 3D display

A micro-projection dynamic backlight for multi-view three-dimensional(3D)display is proposed.The proposed backlight includes a light emitting diodes(LEDs)array,a lenticular lens array,and a scattering film.The LED array,the lenticular lens,and the scattering film construct a micro-projection structure.In this structure,the LEDs in the array are divided into several groups.The light from each LED group can be projected to the scattering film by the lenticular lens and forms a series of bright stripes.The different LED groups have different horizontal positions,so these bright stripes corresponding to different LED groups also have different horizontal positions.Therefore,they can be used as a dynamic backlight.Because the distance between the LEDs array and the lenticular lens is much larger than the distance between the lenticular lens and the scattering films,the imaging progress will make the width of the bright stripes much smaller than that of the LEDs,and the pitch of the stripes is also decreased.According to the 3D display theory,the bright stripes with small width and pitch help to increase the number of views.Therefore,the proposed micro-projection dynamic backlight is very suitable for multi-view 3D display.An experimental prototype was developed,and the experimental results show that the micro-projection dynamic backlight can correctly complete the directional projection of the parallax images to form a 3D display.

改进MSRCR的透明物体逆光图像增强算法

针对透明物体逆光图像对比度低、可视质量差、部分区域过度曝光、边缘信息模糊等问题,提出了一种改进MSRCR(Multi-Scale Retinex with Color Restoration)的透明物体逆光图像增强算法。首先,在MSRCR算法的基础上添加最小可觉差的倒数作为光照分量的调节因子,解决图像的色偏问题,得到准确清晰的透明物体边缘信息;然后,利用自适应对比度增强算法对原图像进行处理,得到亮度适中,对比度高的图像;最后,将两幅图像按亮度均值比例进行拉普拉斯金字塔融合,并进行线性拉伸。将该算法应用于安瓿瓶视觉尺寸测量,结果表明:改进MSRCR的透明物体逆光图像增强算法,能有效解决MSRCR算法的色偏问题,突显透明物体边缘细节信息,并保留亮度增强效果,将安瓿瓶的尺寸误差由0.35 mm降低到0.1mm,提高了透明物体尺寸测量精度。

基于背光显示应用的高量子效率窄带绿光荧光粉Mg_(0.388)Al_(2.408)O_(4):Mn^(2+)

目的:研究Mg_(0.388)Al_(2.408)O_(4):Mn^(2+)荧光粉的发光性能以及在宽色域背光显示领域的应用前景。方法:采用高温固相法合成了Mg_(0.388)Al_(2.408)O_(4):Mn^(2+)荧光粉,并对其物相结构、光致发光特性以及热稳定性进行了研究。结果:该荧光粉具有260~510 nm的宽激发带,最强的激发峰在蓝色光谱区,表明Mg_(0.388)Al_(2.408)O_(4):Mn^(2+)绿光荧光粉可以被商用蓝光芯片有效激发。在紫外光和蓝光的激发下,样品表现出明亮的绿色发射,其拥有较窄的半高宽(FWHM=40.4 nm),较高的色纯度(75.85%)和量子效率(81.5%),计算得到的Huang-Rhys因子表明样品具有较低的电子-声子耦合强度以及较好的热稳定性。制备的LED器件,色域可达118.2%的NTSC。结论:Mg_(0.388)Al_(2.408)O_(4):Mn^(2+)荧光粉在宽色域背光显示领域具有广阔的应用前景。

全自动ZBZ-15车载背光组装机的开发设计

介绍了一种车载背光单元前工序组装机,该设备主要是将基板固定胶、二维码标签贴在金属背板反面,再把反射固定胶、反射片、导光板固定胶、导光板、膜材固定胶组装在金属背板正面。分析了该设备的研发背景、工作原理、结构特点和几项关键技术,有效提高了设备的组装稳定性,提升了背光源的品质,同时,提高了设备的生产效率,提升了产品的市场竞争力。

背光模组膜材折边的关键工艺

随着液晶显示技术(LCD)的快速发展,背光模组的组装精度是提升显示效果和产品可靠性的关键因素。针对背光模组组装中膜材折边的技术难点进行了深入研究,提出了一种创新的三次折边技术,以解决膜材折边过程中的角度控制和回弹量管理问题。通过对材料折边回弹量与折边压力、折压时间、过折角度等因素的关系进行力学仿真计算和试验验证,开发了一种膜材仿形折边机构,实现了折边过程的精确控制。该技术通过预折、初压和复压三个阶段,有效控制了折边角度偏差,可保持在±1.5°,显著提高了背光模组的组装精度。试验结果表明,该技术不仅提升了生产效率,降低了物料损耗和返修率,还确保了背光模组的光学性能,为液晶显示器的高性能和可靠性提供了坚实的基础。

Real-time pupil tracking backlight system for holographic 3D display(Invited Paper)

We propose an automatic three-dimensionM （3D） pupil tracking backlight system for holographic 3D display system with large image size and full-parallax accommodation effect. The proposed tracking module is applied to a holographic 3D display system with two sets of directional holographic imaging module composed of 2 × 2 large scale lens array and 22-inch high-resolution liquid crystal display 3D panel. System architecture is described and experimental results are presented.

转盘式背光源贴膜机的对位系统设计

背光源贴膜设备,主要是将下扩散膜、下增光膜、上增光膜、上扩散膜、遮光膜组装到背板半成品上。为了提高生产效率,提出了一种转盘式贴膜方式。为了降低设备成本,开发了一种既经济又高效的4点对位技术。通过实践应用,该设备能满足生产需求、提高生产效率、节约成本,提高企业在同行业中的竞争力。