Design considerations for highly efficient edge‐lit quantum dot displays

Quantum dots (QDs) are increasingly the technology of choice for wide color gamut displays. Two popular options to incorporate QDs into displays include on‐edge and on‐surface solutions. The opto‐mechanical design for an on‐edge QD solution including a LED light bar (“on‐edge QD light bar”) is more complex than the design for a standard white phosphor LED light bar. In this paper, we identify and investigate a range of design parameters for an on‐edge QD light bar, and we show that these parameters have significant influence on system efficiency and color uniformity. The effects of varying these parameters are explored through the use of a custom adjustable testbed and optical raytracing methods. Our testbed data demonstrate the inherent trade‐offs between efficiency and color uniformity and provide guidance for the design of high‐performing displays. The optical raytracing data demonstrate a good predictive capability and support the use of optical modeling methods for a detailed exploration of a wider range of design parameters.     

中心定位可调节模具在背光源叠片机中的应用

目前,在大多数的多工位自动背光源叠片机械设备中,都是针对一种型号的产品专门有一套模具与之相对应,而且每更换一种模具都要花费很长的时间来重新调试设备,在实际的生产过程中要面临的产品种类少则几十种、多则几百种,甚至每天要有几种产品更换。因此,一种型号的产品对应一套模具的方式不但成本高,而且更换麻烦。针对这一问题,文章提供了一种能够同时满足一定尺寸范围内产品要求的可调节模具来解决。     

半户外液晶显示用高亮直下式LED背光设计

开发了一款用于半户外液晶显示的117cm(46in)直下式背光结构,采用中功率、高显色指数的LED光源,在不使用发散透镜的情况下,使得光源阵列的混光距离在25mm以内,中心亮度可达到20 000cd/m2以上。通过对LED阵列的光学以及驱动和散热设计,实现了一种具有高亮度、高显色画质、散热好、低成本的直下式背光源的方案设计,为户外和半户外液晶展示屏应用提供了支持。     

Design and fabrication of a micropatterned polydimethylsiloxane (PDMS) light‐guide plate for sheet‐less LCD backlight unit

Abstract— A polydimethylsiloxane (PDMS) light‐guide plate (LGP) having micropatterns with an inverse‐trapezoidal cross section was developed for a sheet‐less LCD backlight unit (BLU). The micropatterned PDMS LGP was fabricated by backside 3‐D diffuser lithography followed by two consecutive PDMS replication processes: photoresist‐to‐PDMS and PDMS‐to‐PDMS replications. The fabricated LGP showed an average luminance of 2878 nits and a uniformity of 73.3% in a 2‐in. backlight module with four side‐view 0.85‐cd LEDs. It also could feasibly be applied to a light source for flexible displays owing to the flexible characteristic of the PDMS itself.     

背光源的发展趋势(续完)(第二部分)

侧重介绍了LCD背光源用的光源的功耗。除了荧光灯（FLs）外还介绍了场致发射显示器（FEDs）、发光二极管（LEDs）和有机发光二极管（OLEDs）的原理、特性及优缺点比较。讨论了一维光源（管状光源）和二维光源（面光源）在LCDTV中应用的可能性。管状光源分为冷阴极荧光灯（CCFLs）、外电极荧光灯（EEFLs）和热阴极荧光灯（HCFLs）。指出Philips照明公司的扫描型HCFLs用于背光源是改善LCDTV图像质量的一个方向。FEDs、OLEDs和LEDs都可作为二维背光源用于LCDTV中,但是目前只有LEDs被用于LCDTV中的BLU。     

Switching directional BLUs for full‐resolution auto‐stereoscopic 3D/2D and 2D/3D LCDs

Directional backlight unit (BLU) design concept was applied to realize full‐resolution field alternate auto‐stereoscopic liquid crystal displays (LCDs) with built‐in 3D/2D and 2D/3D. The application‐oriented BLU design requires priority in realizing 2D mode or 3D mode. The switching characteristic of BLU with two confronting illuminating sets was applied to build 2D mode into 3D display and 3D mode into 2D display. An LCD with 2D mode as primary function requires higher double‐sided luminance uniformity than 3D mode. On the other hand, an LCD with 3D mode requires higher single‐sided luminance uniformity than 2D mode. For increasing the double‐sided luminance uniformity for 2D mode as a primary function of the display, the former BLU design was realized by using uniform prismatic structure, that is, using uniform bilateral prismatic structure with a cross section of isosceles triangle on the back surface of the light‐guide plate. For increasing single‐sided luminance uniformity for 3D mode as a primary function of the display, the latter was realized by using graded angle design, that is, unilateral prisms with a cross section of a scalene triangle on the back surface of the light‐guide plate. The LCDs of small‐sized‐handheld game devices and still cameras were fabricated using the 3D/2D and 2D/3D displays.     

薄型化背光源顶白形成机理探讨及改善

介绍了背光源顶白不良,探讨了顶白的形成机理。研究发现表面光滑反射片对导光板网点间留白区域的挤压是产生顶白的根本原因。由此提出通过改善背板局部凸起高度和增加反射片粗糙度来改善顶白。结果表明:顶白发生率随背板局部凸起高度降低和反射片表面粗糙度增加而明显降低。控制模具凸棱厚度可调整回压量,进而降低背板局部凸起高度。模具凸棱厚度为0.05mm时,背板局部凸起高度均值由无回压时的0.21mm降低至0.11mm,加速试验条件下对应顶白发生率由50%降低至18.7%;涂布不同大小粒子可调整反射片表面粗糙度。当反射片涂布Bead粒子径为40μm,对应粗糙度为6.29μm时,并搭配段差回压后背板,改善后背光源在加速试验条件下无顶白发生。同时,经光学、老化及振动测试,改善后背光源未发现其它相关不良。     

A directional backlight with narrow angular luminance distribution for widening the viewing angle for an LCD with a front‐surface light‐scattering film

Abstract— A directional backlight unit has been developed to widen the viewing angle of a TN‐LCD with a front‐surface light‐scattering film/layer. The novel directional backlight has a diagonal of 34 cm and is structured by light‐direction‐control optical micro‐features and an inverted prism film. The backlight has a symmetrical round luminance cone of ±9° and a uniform spatial distribution of 88%. By using this backlight unit in combination with an LCD, the narrow cone resulted in widening of the TN‐LCD's viewing angle up to 120° at full width at half‐maximum.     

背光源的发展趋势(第一部分)

介绍了LCD背光源的市场及技术的发展。LCD已广泛用于手机、计算机显示器、笔记本电脑，目前正在冲击TV市场，预计LCD的快速增长将持续到2010年。因此LCD背光源模组也会得到快速增长。 讨论了带有CCFL、EEFL、HCFL以及LED的背光源。扫描型HCFL背光源可改善LCDs的图像质量，LED背光源则可获得大的色域，但是它们的功耗仍然大于CCFL，而且成本也很高。     

Novel light‐extraction film

Abstract— A novel extractor's application to backlight‐unit (BLU) architectures of different size and application is presented. Critical material and design parameters are discussed. Seemingly trivial changes in design to accommodate different sizes and lighting geometries result in dramatic performance changes.