Design Constraints on FSC LCD

Design constraints on field-sequential color liquid crystal displays (LCDs) are proposed and compared with those of conventional color filter LCDs. Application of these constraints to the design of LCD screens is demonstrated.     

A new COG technique using low temperature solder bumps for LCD driver IC packaging applications

A new chip on glass (COG) technique using flip chip solder joining technology has been developed for excellent resolution and high quality liquid crystal display (LCD) panels. The flip chip solder joining technology has several advantages over the anisotropic conductive film (ACF) bonding technology: finer pitch capability, better electrical performance, and easier reworkability. Conventional solders such as eutectic Pb-Sn and Pb-5Sn require high temperature processing which can lead to degradation of the liquid crystal or the color filter in LCD modules. Thus it is desirable to develop a low temperature process below 160/spl deg/C using solders with low melting temperatures for this application. In our case, we used eutectic 58 wt%Bi-42 wt%Sn solder for this purpose. Using the eutectic Bi-Sn solder bumps of 50-80/spl mu/m pitch sizes, an ultrafine interconnection between the IC and glass substrate was successfully made at or below 160/spl deg/C. The average contact resistance of the Bi-Sn solder joints was 19m/spl Omega/ per bump, which is much lower than the contact resistance of conventional ACF bonding technologies. The contact resistance of the underfilled Bi-Sn solder joints did not change during a hot humidity test. We demonstrate that the COG technique using low temperature solder joints can be applied to advanced LCDs that lead to require excellent quality, high resolution, and low power consumption.     

Transflective liquid crystal displays

In this review paper, a detailed overview of the transflective liquid crystal display (LCD) technology is presented. We first introduce the transflector classifications based on their composition and properties. Then, in reviewing the development history, we investigate the mainstream transflective LCDs, including their operating principles, advantages, and disadvantages. Finally, the image quality issues of transflective LCDs, such as color balance, image brightness, and viewing angle, are discussed.     

The flat panel's future

The development of active-matrix liquid crystal displays (AMLCDs) to overcome the limitations of passive LCDs is reviewed. The decision of video graphics adapter (VGA) versions of these displays, the market for these displays, and the companies involved in producing them are discussed. Two alternatives to AMLCDs, one involving a method for driving passive LCDs that would give them most of the benefits of active-matrix displays and the other involving standard passive-matrix color LCDs, are also discussed. The possibility of transferring LCD technology to the high-definition television (HDTV) market and the most likely candidate for that market, plasma display panels (PDPs), are examined     

Wide-View MVA-LCDs With an Achromatic Dark State

A multi-domain vertical alignment liquid crystal display (MVA LCD) using a negative C-plate and a biaxial film is proposed to obtain an achromatic dark state. In comparison to conventional approach which uses a negative C-plate and a positive A-plate, the maximum light leakage over entire viewing cone is reduced by ~ 6X at lambda = 450 nm and ~ 4X at lambda = 650 nm. The achromatic dark state is essential for improving the contrast ratio, viewing angle and color saturation of MVA LCDs.     

白光有机发光器件研究及进展

有机电致发光技术被认为是可能替代液晶的新一代显示技术，白光有机发光器件由于可应用于液晶显示的背光源、普通照明、特殊光源以及实现全彩色有机发光显示而倍受瞩目。本文对白光有机电致发光器件的结构、工作原理等进行了简单的概述并总结了白光有机发光器件的最新进展。     

Backward Color Device Model for the Liquid Crystal Displays With Primary Shift and Two-Primary Crosstalk

The chromaticity characteristics of the liquid crystal displays (LCDs) with primary shift and two-primary crosstalk can be described by a set of simultaneous nonlinear algebraic equations. This set of equations is the forward color device model that converts signals into output tristimulus values. It is required to solve the set of equations for implementing the backward color device model that converts tristimulus values into signals. An iteration method for solving the equations is studied. Two LCD monitors are taken as examples for testing the backward color device model. The results show that the average color differences of backward and forward color device models are of the same level. The required numbers of iteration times are 4 and 6 for the two tested LCD monitors, where the LCD monitor with larger two-primary crosstalk requires more number of iteration times.     

展宽LCD视角的新原理

扭曲向列型（ＴＮ）和超扭曲向列型（ＳＴＮ）ＬＣＤ，包括有源和无源矩阵，都有一个共同的缺点，即视角狭窄；审液晶材料的电光特性所造成的。现已开发出一种展宽ＬＣＤ视角的新方法，这一ＬＣＤ新的工作原理在解决其视角狭窄的问题时，对于ＬＣＤ显示器件而言，不是从其内部着手而是从其外部着手，本文将描述这种新型设计的各关键元件的工作原理。     

无阈值铁电液晶

简要介绍铁电、反铁电液晶的发现、发展、显示应用中遇到的问题以及近来发展起来的无阈值铁电液晶的研究结果,最后讨论无阈值铁电液晶应用前景。     

STN—LCD中双折射着色现象的消除—白模式显示

在液晶显示领域中一项重要的进展是 STN-LCD 的开发,用简单矩阵驱动可实现大信息容量。但是 STN-LCD 利用液晶材料的双折射效应,产生显示着色问题,使显示对比度下降。为获得较好的显示质量必须设法消除这种固有着色现象。本文主要讨论用光学补偿法消除着色的原理,并着重介绍用单向延伸的聚合物制成的相位延迟膜的光学特性,将其应用于 STN-LCD,可获得良好的黑白显示。在此基础上与微型彩色滤色器结合可获得多色显示。     

Adaptive LC/BL Feedback Control in Field Sequential Color LCD Technique for Color Breakup Minimization

A full-color image on field sequential color (FSC) displays is composed of color fields in temporal sequence. With the FSC mechanism, color filters of liquid crystal displays (LCDs) can be removed to heighten the light efficiency and lower the material cost. Color breakup (CBU), however, has appeared intrinsically to degrade visual qualities. A novel gray level determination of liquid crystal and backlight (LC/BL) was proposed to suppress the CBU artifact on FSC-LCDs. Based on the image content in each frame, a dominated color-mixed field was found to minimize the color difference between the CBU and original image. Additionally, the feedback algorithm for the adaptive LC/BL signals was developed and implemented on a 32-inch optically compensated bend (OCB) mode LC panel. According to the evaluation of experiments and observations, the proposed method has been demonstrated to greatly suppress CBU in LCD applications.      

How far has the molecular alignment of liquid crystals been elucidated?

Liquid crystal displays (LCDs) - born in late 1960s - have become a 45 billion-dollar industry in 2004. Today's LCD panels cover a wide range of sizes from 0.2 to 82 in diagonal. The electro-optical characteristics of any field effect LCD are determined by the orientation of its liquid crystal (LC) molecules at the display boundaries. Until recently most LCD alignment processes were based on rubbing polymer coated LCD substrates with a cloth. Despite its key importance, the complex mechanism governing the alignment of LC molecules on display substrates is still not well understood. Do the microgrooves generated by rubbing induce LC-alignment or does the stretching of polymer chains as a result of brushing cause it? To overcome the drawbacks of conventional aligning techniques, new alignment processes have recently been proposed and developed. Examples are micro embossing, ion bombardment, fringe field effects and photo-alignment. In this paper, some mechanisms of LC alignment are discussed and various alignment techniques and methods to investigate the interaction of LC molecules with substrates are reviewed.     

Design and Evaluation of Light Spread Function for Area-Adaptive LCD System

A methodology, based on two-dimensional super-Gaussian light spread functions (LSFs), was studied for the light-emitting-diode (LED) backlighting system in the high dynamic range (HDR) liquid crystal displays (LCDs). We proposed a novel LED-based optomechanical configuration to implement the desirable luminous pattern. A dual-liquid-crystal-panel system was constructed as a pseudo-HDR LCD to evaluate the super-Gaussian illumination. The proposed HDR scheme was verified via the current platform: overall luminance uniformity, contrast ratio and processing speed could be improved by factors of 1.55, 1.95–4.15, and 4.82, respectively. The design flexibility made the methodology applicable to any panel dimension and backlight division of the HDR LCDs, and to the conventional full-on backlighting LCDs as well.      

单玻璃基板与各向异性聚合物膜的IPS-LCD的应用

介绍了一种使用单片玻璃基板和各向异性聚合物膜的轻型、共面转换液晶显示(IPS-LCD)技术。液晶分子由伸长的聚合物膜内的颗粒排列。各向异性聚合物膜的取向性能与聚酰亚胺(PI)摩擦层相当。良好的液晶取向性能使新器件的对比度(514:1)、驱动电压和响应时间都能够与双玻璃基板LCD相比拟。这种各向异性膜也能作为拓宽视角的相位补偿膜来使用。该技术特别引人注目之处在于制作单基板显示器,同时它也具有实现双层宾主显示和IPS-LCD柔性显示的潜在应用。     

不同屏幕贴膜对显示效果的影响比较

为了定量分析屏幕贴膜前后彩色三要素的变化,分别测量不同色温(2 700~6 500K)下液晶显示器(LCD)与有机发光二极管(OLED)屏幕的光谱分布。根据聚对苯二甲酸乙二醇脂树脂(PET)及脉冲电子束沉积(PED)贴膜透射率数据,拟合屏幕光谱分布及贴膜透射率函数表达式。计算并定量比较两种贴膜对不同色温下两种屏幕1931CIE XYZ色坐标、主波长、饱和度及光通量的影响,结合人眼分辨率对计算比较结果进行分析。两种贴膜可分别使LCD色坐标Z值降低0.001 4、0.000 6,使OLEDZ值下降0.000 2左右,降幅不随色温变化;色温5 000K时,两种贴膜均使LCD主波长降低1nm,OLED主波长增加1nm;当色温设置低于5 000K时,两种贴膜分别可使LCD饱和度增加约0.37%、0.17%;两贴膜可使不同色温LCD及OLED光通量分别下降11.9%、1.46%。PET贴膜对光通量的影响,人眼能够明显辨别。以上结论可为屏幕贴膜的选择与使用提供依据,分析研究方法可为相关产品的研发提供借鉴。     

IPS-LCD using a glass substrate and an anisotropic polymer film

A lightweight in-plane-switching liquid crystal display (IPS-LCD) using a single glass substrate and an anisotropic polymeric film is demonstrated. The liquid crystal molecules are aligned by the elongated polymer grain of the film. The alignment capability of the anisotropic film is comparable to a buffed polyimide layer. Compared to the LCD using two glass substrates, our new device exhibits a comparable contrast ratio (/spl sim/514:1), driving voltage, and response time because of good LC alignment. Such an anisotropic film can also function as a phase compensation film for widening the viewing angle. This technology is particularly attractive for making single-substrate displays and also has potential for a double-layered guest-host display and a flexible display using IPS LCDs.     

多晶硅薄膜晶体管液晶显示器件的优化设计

针对多晶硅薄膜晶体管液晶显示器件关态漏电流较大的问题,采用源漏轻掺杂结构以降低关态时电荷的泄漏,增加晶体管的开关电流比值,通过模拟轻掺杂区不同的物理参数,如掺杂浓度及掺杂区宽度等,研究薄膜晶体管的开关电流比值,由此确定像素各部分的尺寸,对液晶显示器件进行优化设计。     

Dynamic Pixel Models for a‐Si TFT‐LCD and Their Implementation in SPICE

A dynamic analysis of an amorphous silicon (a‐Si) thin film transistor liquid crystal display (TFT‐LCD) pixel is presented using new a‐Si TFT and liquid crystal (LC) capacitance models for a Simulation Program with Integrated Circuit Emphasis (SPICE) simulator. This dynamic analysis will be useful when predicting the performance of LCDs. The a‐Si TFT model is developed to accurately estimate a‐Si TFT characteristics of a bias‐dependent gate to source and gate to drain capacitance. Moreover, the LC capacitance model is developed using a simplified diode circuit model. It is possible to accurately predict TFT‐LCD characteristics such as flicker phenomena when implementing the proposed simulation model.     

平面介质阻挡Xe放电荧光灯型LCD背光源的新进展

近年来随着大屏幕液晶显示器的快速发展，对背光源性能的要求也越来越高，使得各种新型背光源不断被开发出来。平面介质阻挡Xe放电荧光灯因其具有优越的光电特性，可望被用于台式电脑液晶显示器和液晶电视中。本文对具有代表性的几种新型平面介质阻挡Xe放电荧光灯进行了介绍，分析了进一步提高放电灯性能需要解决的问题。     

应用于LCD的平栅型碳纳米管场致发射显示器背光源的研制

采用磁控溅射、光刻和湿法刻蚀技术制备平栅型场发射阴极阵列,利用电泳将碳纳米管(CNT)发射源沉积在阴极表面,将阴极板和阳极板封接后制成51cm单色平栅型CNT场致发射显示器(CNT-FED),作为背光源模板应用于49 cm液晶显示器(LCD)器件中.场发射测试表明,器件在阳极电压3 500V、栅极电压290 V时,阳极...