The flowering of flat displays

The author describes how new and improved display technologies are giving electronics a fresh look. Active-matrix liquid crystal displays (LCDs) with improved image quality and larger viewing angles are on the verge of replacing CRTs, while reflective displays (with very low power consumption) and cholesteric displays (which need no power to retain an image) are making new portable products possible     

Quantitative Comparison of Color Performances Between IPS and MVA LCDs

Color gamut and color shifts of the film-compensated multi-domain in-plane-switching (IPS) and multi-domain vertical alignment (MVA) liquid crystal displays (LCDs) are calculated quantitatively using light-emitting diodes (LEDs) and cold-cathode fluorescent lamp (CCFL) backlight. Simulation results indicate that the LED backlight exhibits better angular color uniformity and smaller color shifts than CCFL. In addition, the color gamut can be further widened and the color shift reduced when using color-sequential RGB-LED backlight without color filters. In general, both IPS and MVA LCDs show relatively small color shift under different backlights, but MVA has a lower color shift using the optimized uniaxial compensation films     

Design Considerations Between Color Gamut and Brightness for Multi-Primary Color Displays

Color displays show a vivid colorful image by combination of three or above primary colors on every individual pixel. Brightness of color displays, however, strongly restricts the color gamut of displays. From the color mixing theory, the area of color gamut on the color coordination would shrink smaller when brightness grows up. At the maximal brightness, displays can show one system white point only. The difficulties how to obtain the maximal brightness under an assigned color point or color gamut have been a key issue for display manufacturers. The paper proposes a theory to analyze the relation between brightness and color gamut based on the multi-primary color display. Simulations estimate the boundary of color gamut of multi-primary color displays under required brightness which had been proved by experimental results of tri-primary color display. The theory can be applied on the color temperature (CT) design which experimental results show the fact that a display apparatus with higher color temperature could sacrifice brightness less compared to one with lower color temperature when color temperature of the display image needs to change. The theory provides a design guideline for optimization between color gamut, color temperature and brightness on multi-primary color displays     

Ultrawide-view liquid crystal displays

The wide viewing angle technologies for liquid crystal displays (LCDs) are reviewed. The most promising liquid crystal modes for wide view technologies, such as in-plane switching, multidomain vertical alignment, patterned vertical alignment, and advanced-super-view are compared. By optimizing the phase-compensation films and their device configurations, the ultrawide-view LCDs with a contrast ratio higher than 100:1 at /spl plusmn/85/spl deg/ viewing cone are demonstrated.     

CRT与LCD技术的视觉刺激显示性能评价

为了定量评价两种技术在视觉研究实验中的适用性,本文根据文献分析和视觉研究需求设计了显示器性能测试系统与测试流程,对一台阴极射线管(CRT)显示器和两台通用液晶显示器作为视觉刺激显示设备的关键性能进行测试。结合心理物理学理论,特别是韦伯定律,详细地分析和比较了各项测试结果。实验结果显示所有的显示器有不同的Gamma特性,需要进行相应的Gamma校正之后才能线性呈现图像的灰度级;CRT显示器在响应时间上具有绝对优势,但屏幕空间均匀性和独立性较差;相比于CRT显示器,LCD显示器具有较高的亮度和较好的空间均匀性和独立性,但是响应时间偏慢,而且相邻两帧图像之间独立性较差。这些测试结果表明,CRT显示器仍然是高动态特性视觉刺激显示的首选,而LCD显示器可以用于呈现对空间亮度一致性和空间的独立性要求高,但对响应速度要求不高的视觉刺激。     

Revolution of the TFT LCD Technology

The introduction of flat panel displays that are fabricated with thin-film-transistor liquid-crystal displays (TFT LCDs) has changed human's lifestyle very significantly. Traditionally, the revolution of the TFT LCD technology has been presented by the timeline of product introduction. Namely, it first started with audio/video (AV) and notebook applications in the early 1990s, and then began to replace cathode-ray tubes (CRTs) for monitor and TV applications. Certainly, TFT LCDs will continue to expand in all areas of our daily life in the future. Here a new concept of the revolution of the TFT LCD technology is presented for the major TFT LCD makers. In this new concept, there are four waves of technology revolution with the following themes, respectively: 1) product introduction; 2) performance enrichment; 3) power and material utilization; and 4) functions for human interface. The role of the LCD-TV in the revolution is also discussed.     

数字电视宽色域测量的色块校准方法

数字电视显示器的宽色域技术是显示领域的发展方向.近年来,宽色域显示器件和显示方式有长足进步,以发光二极管为背光源的液晶显示器等已商品化.采用三维色域测量方法,可以比传统测量方法更加准确地衡量产品的色域.提出了利用显示器宽色域色块校准方法,解决三维色域测量的准确性问题.     

LED显示屏的色域校正

LED发光在亮度和色度上有一定的离散性,会明显降低LED显示屏的图像质量。文章给出了一种色域校正方法,能在改善LED显示屏的亮度、色度均匀性的同时,确定LED显示屏的显示色域。建立了LED显示屏显示颜色的线性数学模型,对LED显示屏色域校正的目标色域进行了分析,给出了将LED屏幕所有显示像素的显示色域范围校正到目标色域的方法,并通过"白平衡"来实现对颜色色坐标的精确控制。实验结果显示,该方法可以将LED显示屏显示色域精确校正到目标色域。     

高发光效率电视的竞争

从最关键的显示特性（发光效率）的角度逐一分析了当前相互竞争的LCD、CRT、PDP、投影技术、FED、SED以及OLED等主流显示技术，每种技术都有取得领先机会的优势，但究竟谁会最终胜出？     

彩色显示器的通道独立性分析

彩色显示器在色彩管理中的转换模型都是建立在RGB三刺激值的可加性原理之上的，但是在实际应用中由于RGB三个通道之间存在相互干扰，使得红绿蓝的颜色合成结果在一定程度上偏离了叠加原理，实验表明，红绿蓝三个通道之间的干扰主要表现为一种相互抑制作用，而且造成的彩色显示器色彩转换模型的色差随显示亮度的增加而加大。因此，在色彩管理的模型转换中必须考虑这一误差，在平时的使用中一定要尽量避免让显示器工作在太亮的区域。     

彩色显示器亮度和对比度的最优化设置

实验研究了彩色显示器亮度和对比度设置对显示器颜色特性的影响.将Neso彩色显示器的亮度和对比度分别设置为最大值的20、50、80和100 %共16种组合,详细地测试和比较了每种设置下显示器的黑点亮度、白点亮度、阶调再现曲线(TRC)、通道可加性、色域和色品恒定性等颜色特性,实验结果表明,亮度设置对黑点亮度影响明显,对比度设置主要影响的白点亮度,黑点对通道可加性、色域和色品恒定性影响很大.通过亮度、对比度设置使黑点亮度尽可能小,白场亮度达到使用要求,同时TRC不出现"横剪切"和"纵剪切"现象,则显示器达到了最优化设置.     

Development of CRT＇s corner cutting repair systems

CRT Corner cutting tube is considered as a definitive reject and will be sent to reclaim at all times. It caused lots of material loss. In this paper, a novel technology used to save CRTs corner cutting tube is presented firstly. A set of repair system has been successfully developed to repair CRTs corner cutting tube. Then, the process technology for corner cutting repair has been excogitated by empirical studies. Finally, the correlative performances of repaired tube are evaluated. The experimental results show that the quality of repaired tube has no difference with that of normal product. The repair yield has reached above 97 percent. This new technology has contributed to improving the production yield, reducing the material consumption and decreasing the cost of color CRT production.     

基于阿尔法形态的显示器三维色域体积快速算法

随着各种宽色域显示设备的出现,越来越需要高效准确的色域比较评价方法。三维色域由于包含了亮度信息,与二维色域相比,能够更全面地展示、比较色域差异。但由于其形状不规则,三维色域的计算较困难,高计算复杂度限制了三维色域评价在实时性要求较高的工程领域的应用。实现了基于阿尔法形态的三维色域体积计算方法。实验结果表明,通过仔细选择半径参数,能够以较低计算复杂度准确计算不规则三维色域体积。与基于准蒙特卡洛的体积计算方法相比,基于阿尔法形态的方法更适合实时应用。     

彩色成像亮度计用于显示测量及其不确定度分析

彩色成像亮度计能在几秒钟之内一次完成数以万计个物点的测量,因此它非常适合于测量显示器的亮度、颜色及其分布.分析了彩色成像亮度计测量 CRT 和 LCD 显示器的不确定度,主要分析了光谱失配所引入的不确定度,结果表明系统响应的光谱失配造成了较大的测量不确定度.介绍了一种应用于彩色成像亮度计测量 CRT 和 LCD 显示器的光谱校正方法,结果表明这种校正方法能有效减少测量不确定度.     

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     

Representations of Relative Display Gamut Size

Gamut size of a wide gamut display is usually represented with the ratio of its chromaticity triangle area and the chromaticity triangle area of a standard display in CIE xy color coordinates. Such a chromaticity area ratio (CAR) is a rough relative gamut size, because CIE xy is a nonuniform color coordinate system and display gamut is a volume in color space. The representation of relative gamut size with the ratio of the discernible color numbers in a display gamut and NTSC TV gamut is studied. This ratio is called the discernible color number ratio (DCNR). Discernible color number is counted with CIE94 color difference formula in CIELAB color space. It is found that CAR is larger than DCNR for the display with primary purity higher than NTSC primary purity. For example, the CAR of a practical light-emitting diode (LED) display with respect to NTSC TV is 7.8% overestimated, in which red, green, and blue LED primary wavelengths are 625, 520, and 470 nm, respectively; red, green, and blue LED bandwidths are 20, 40, and 30 nm, respectively. In addition, the DCNRs of wide gamut displays with respect to the object color of the same white illuminant are investigated. It is shown that the gamut size improvement for laser display compared with LED display is not significant.     

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.     

Two-dimensional transforms for device color correction and calibration.

Color device calibration is traditionally performed using one-dimensional (1-D) per-channel tone-response corrections (TRCs). While 1-D TRCs are attractive in view of their low implementation complexity and efficient real-time processing of color images, their use severely restricts the degree of control that can be exercised along various device axes. A typical example is that per separation (or per-channel), TRCs in a printer can be used to either ensure gray balance along the C = M = Y axis or to provide a linear response in delta-E units along each of the individual (C, M, and Y) axis, but not both. This paper proposes a novel two-dimensional color correction architecture that enables much greater control over the device color gamut with a modest increase in implementation cost. Results show significant improvement in calibration accuracy and stability when compared to traditional 1-D calibration. Superior cost quality tradeoffs (over 1-D methods) are also achieved for emulation of one color device on another.     

IPS-LCD电视中LED背光源的RGB色彩控制系统

带RGB-LED背光系统的32inAS-IPS液晶电视被开发出来了,它可以调节每个主背光源的亮度,并可以对每帧中的原像数据进行转换。红色、绿色和蓝色背光的亮度根据输入的图像数据分别进行调节。图像数据按照调节后的背光亮度进行转换。因此,动态对比度和低灰度的色域均得到很大的改善。     

The dawn of organic electronics

Organic semiconductors are poised to transform the world of circuit and display technology. Major electronics firms such as Philips and Pioneer, and smaller companies such as Cambridge Display Technology, Universal Display, and Uniax, are betting that the future holds tremendous opportunity for the low cost and sometimes surprisingly high performance offered by organic electronic and optoelectronic devices. Using organic light-emitting devices (OLEDs), organic full-color displays may eventually replace liquid-crystal displays (LCDs) for use with laptop and even desktop computers. Such displays can be deposited on flexible plastic foils, eliminating the fragile and heavy glass substrates used in LCDs, and can emit bright light without the pronounced directionality inherent in LCD viewing, all with efficiencies higher than can be obtained with incandescent light bulbs