电视背光灯设计-翻译

电视背光灯设计-翻译 苏州大学本科生()附件:外文文献资料与中文翻译稿 外文文献资料 收集:苏州大学 应用技术学院 10电子,学号1016405036, [岳嵩] Research on Color Matching of LED Backlight for Large-Color-Gamut LCD Application Comparing with the conventional CCFL (Cold Cathode Fluorescent Lamp) backlight, three-basic-color LEDs backlight has some advantages such as good color reproduction, long life and lead free etc. Theoretically, the color gamut is determined by x, y coordinates of the three basic colors in CIE chromaticity diagram, and the x, y coordinates of each basic color can derived from the relative spectrum distribution (RSD) of the LED. In this paper, the red, green and blue LEDs’ RSD models are established to calculate and analyze the color gamut of a backlight. By simulating those models,the relationships that the color gamut of a LED backlight varies with each color are analyzed, and the optimum combination of three colors is obtained within the given wavelengths ranges. Moreover, the combinations of three colors for the gamut of 115% NTSC and 110% NTSC are plotted in pictures, respectively. 1. INTRODUCTION In 1931CIE chromaticity diagram, three points corresponding to RGB colors construct a triangle, in which all colors can be reproduced by the three basic colors. Area of that determines the color gamut, and the wider the color gamut is, the more colors the system can reproduced. NTSC is one of the broadcasting standards which were defined based on the colorimetric characteristics of CRT display. In NTSC, standard illumination C or D65 is used, and the three-basic-color coordinates and the color gamut are showed in Fig 1. The color gamut of NTSC system will be hereinafter taken to compare with color gamut of other display systems. 第 1 页 苏州大学本科生毕业设计(论文)附件:外文文献资料与中文翻译稿 Fig1. NTSC:color gamut in chromaticity diagram Recently, CCFL backlights still occupy the dominant status in the area of liquid crystal display, however, CCFL backlights are poor color reproduction and their color gamut only reach about 76% NTSC, and obviously this drawback is making CCFL backlights lose more and more market of LCD backlights. On the other side, the rapid development of LED over the passed few years has opened up the opportunity for LED backlights to substitute for CCFL backlights in liquid crystal display industry for their advantages like good color reproduction, long life and lead free etc. The color gamut of a display can be enlarged by using saturated primary colors, and colors from LEDs are highly saturated because FWHM (Full Wave at Haft Maximum) of LED’s spectrum is narrow. So displays with LED backlights can obtain a wide color gamut, which is usually more than 110% NTSC, and are able to faithfully reproduce the beautiful colors of real life [1-2]. In this paper, we establish the red, green and blue LEDs’ RSD models. Based on the models, the three-color RSDs are simulated by retaining the shapes and shifting the peak wavelengths. Then the color gamut of a lot of combinations of three basic colors is calculated and compared with the color gamut of NTSC. Some groups of combinations of three basic colors which can have wide color gamut more than a certain percent of NTSC color gamut are obtained 第 2 页 苏州大学本科生毕业设计(论文)附件:外文文献资料与中文翻译稿 2. RSD MODELS ESTABLISHED A display’s color gamut is determined by x, y coordinates of its three basic colors. And we can obtain x, y coordinates from following equations: x,X/(X，Y，Z) (1) y,Y/(X，Y，Z) (2) Where X, Y, Z are the tristimulus values which correspond to human eyes’ feeling to RGB colors respectively. And the tristimulus values can be obtained by calculating the integral of RSD and spectral tristimulus values follow as: X,k()x'()d,,,, ,, (3) Y,k,(,)y'(,)d, ,, (4) Z,k,(,)z'(,)d, ,, (5) Where k is normalized factor,θ(λ) is the relative spectrum distribution, and ,,are spectral tristimulus values of CIE standard x'()z'(),y'(,), observers.From equations (1)-(5) above, we know that RSDs determine colors’ chromaticity coordinates,and subsequently confirm the color gamut of a display system. The main parameters which influence the devices’ RSDs are material and structure etc. Approximately, we take λ0.5, the FWHM of RSDs, as a constant, while devices’ material and structure are the same.When the peak wavelength λo and FWHM λ0.5 are known, the RSD of LED can be described as [3]: 22I(,),{exp[,{(,,,)/,,}]，2exp[,5,{(,,,)/,,}]}/3 00.500.5 (6) Then we measured the RGB LEDs and obtained their x,y coordinates, and noticed that FWHM of them are about 23nm, 40nm,25nm respectively, while their peak 第 3 页 苏州大学本科生毕业设计(论文)附件:外文文献资料与中文翻译稿 wavelengths are around 633nm,525nm,458nm. In order to test the models,substitute the data above for corresponding parameters in equations (6) and then calculate the coordinates and the color gamut. Table.1 gives the calculated results by models and the data measured the real LEDs. Tab.1 the calculated x,y coordinates and color gamut comparing with the measured data From tab.1, error between measured value and calculated value of green LED is so large that the calculated gamut doesn’t close to the real value very well. In order to get a more accurate result, green LED model use a real RSD curvedirectly, whose peak wavelength and FWHM are 525nm and 40nm, which is showed in fig.2. Then by retaining the shape of the RSD curve and shifting the peak wavelength, we used the MATLAB to calculate the x,y coordinates of green LEDs: 525nm, (0.2004, 0.7138); 515nm, (0.1469, 0.6800). So the calculated gamut in the tab.1 change to 118.6% NTSC and 114.0% NTSC respectively, which almost equal to the measured gamut. 第 4 页 苏州大学本科生毕业设计(论文)附件:外文文献资料与中文翻译稿 Fig.2 RSD curve of a real green LED From the RGB RSD models above, color gamut of a three-basic-color LED backlight can follow as: gamunt,gamunt(,,,,,) r0g0bo (7) ,,,Where,, are the peak wavelengths of RGB LEDs respectively. g0r0b0 3. SIMULATION AND ANALYSIS When designing a LED backlight, its luminance must be taken into account as the same as the color gamut. Recently, the luminous efficacy of LED is still low, and its luminance varies with wavelength. So the appropriate ranges of peak wavelengths of three basic LEDs are chosen: 620nm-650nm for red LEDs, 510nm-530nm for green ones and 450nm- 475nm for blue ones.Base on RSD models of the three kinds of LEDs, we calculated and analyzed the combinations of three basic colors,whose peak wavelengths are in the ranges above, to study the relationship ofcolor gamut and the peak wavelengths of the three basic colors. When the peak wavelength of 第 5 页 苏州大学本科生毕业设计(论文)附件:外文文献资料与中文翻译稿 green light is 521nm (corresponding dominant wavelength approximately is 528nm), the color gamut of three-basic-color backlight reaches maximum. And the color gamut increases monotonously as red light peak wavelength increases when those of the green and blue lights stay invariable, but decreases monotonously as blue light peak wavelength increases when those of the green and red lights stay invariable. Moreover, we find that the combination of peak wavelengths (650nm, 521nm, 450nm) is optimum, and its color gamut can reaches more than 120% NTSC. Show in fig.3. Fig.3 the relationship of color gamut and R, G, B wavelength respectively And furthermore, the combinations of three colors for the gamut of 115% NTSC and 110% NTSC are plotted in pictures,show in fig.4 and fig.5 respectively 第 6 页 苏州大学本科生毕业设计(论文)附件:外文文献资料与中文翻译稿 Fig.4 combinations of three colors for the gamut of 115% NTSC Fig.5 combinations of three colors for the gamut of 110% NTSC 4. CONCLUSION In this paper, the relative spectrum distribution models of RGB LEDs are established. Through simulating those models,the relationships that the color gamut of three basic colors LED backlight varies with each color are analyzed, and the optimum combination of three colors is obtained within the given wavelengths ranges. Furthermore, the combinations of three colors for the gamut of 115% NTSC and 110% NTSC are plotted, respectively, and those pictures may offer color combination.an intuitional guidance to choose the appropriate three- 第 7 页 苏州大学本科生毕业设计(论文)附件:外文文献资料与中文翻译稿 中文翻译稿 翻译:苏州大学 应用技术学院 电子,学号1016405036, [岳嵩] 研究配色广色域 LED背光的LCD应用程序 比较与传统张智胜(冷阴极荧光灯)背光,three-basic-color LED背光有一些优势,如良好的色彩再现,寿命长、无铅等。从理论上讲,色域是由x,y坐标的三种基本颜色CIE色度图,与x,y坐标的基本颜色可以来源于相对光谱分布(RSD)的领导。摘要红色,绿色和蓝色发光二极管的RSD模型建立计算和分析背光的颜色范围。通过模拟这些模型的关系,LED背光的颜色范围随每种颜色进行了分析,并得到最佳的三种颜色组合在给定的波长范围。此外,三种颜色的组合的115% NTSC和110% NTSC绘制的图片。 1. 介绍 1931年cie色度图,三分对应的RGB颜色构造一个三角形,所有颜色可复制的三种基本颜色。决定了色域的面积,更广泛的色域,颜色越多系统可以复制。NTSC的广播定义基于比色阴极射线管显示器的特点。在NTSC标准照明使用C或D65和three-basic-color 坐标和色域是显示在图1。NTSC系统将以下的颜色范围比较与其他显示系统的色域 第 8 页 苏州大学本科生毕业设计(论文)附件:外文文献资料与中文翻译稿 图一:NTSC:色域在色度图 最近,张智胜背光仍然占据在液晶显示领域的主导地位,然而,张智胜 背光是可怜的色彩再现NTSC和色域只达到约76%,很明显这个缺点让张智胜背光液晶背光失去越来越多的市场。另一方面,领导通过几年的迅速发展开辟了LED背光的机会代替张智胜背光液晶显示器行业等优势,良好的色彩再现,寿命长、无铅等。显示的颜色范围可以扩大利用饱和原色,从LED是高度饱和和颜色,因为半最大值(全波在牧场最大)LED的光谱是狭窄的。所以与LED背光显示可以获得广泛的色域,通常超过110% NTSC,能够忠实地再现现实生活的美丽色彩[1 - 2]。 在本文中,我们建立了红色、绿色和蓝色发光二极管的RSD模型。基于模型、三色RSDs被保留形状和模拟峰值波长转移。那么大量的色域三种基本颜色的组合计算并与NTSC的色域。一些组织的三种基本颜色的组合可以有宽色域超过一定百分比的NTSC颜色范围。 2. RSD模型建立 显示的色域是由x,y坐标的三种基本颜色。我们可以获得x,y坐标从以下方程: x,X/(X，Y，Z) (1) y,Y/(X，Y，Z) (2) 在X,Y,Z是人类眼睛的三色值对应于RGB颜色分别的感觉。和三色值可以通过计算RSD 第 9 页 苏州大学本科生毕业设计(论文)附件:外文文献资料与中文翻译稿 的积分和光谱三色值为: X,k()x'()d,,,,,, (3) Y,k()y'()d,,,,,, (4) Z,k,(,)z'(,)d,,, (5) k是规范化的因素,θ(λ)是相对光谱分布、和x”(λ),y '(λ)、z(λ)光谱三色值的CIE标准观察者。从方程(1)-(5),我们知道RSDs确定颜色的色度坐标,随后确认的色域显示系统。设备的主要参数影响的RSDs材料和结构等约,我们采取λ0.5,RSDs的半最大值,作为一个常数,而设备的材料和结构都是一样的。当峰值波长λo和半最大值 λ0.5众所周知,RSD的领导可以被描述为[3]: 22 I(,),{exp[,{(,,,)/,,}]，2exp[,5,{(,,,)/,,}]}/300.500.5 (6) 然后我们测量了RGB led和获得他们的x,y坐标,并注意到半最大值约23海里,40 nm,分别25纳米,而峰值波长633 nm左右,525 nm、458 nm。为了测试模型,用上面的数据代替相应的参数方程(6),然后计算坐标和色域。怎么让模型的计算结果和数据测量了真正的发光二极管。 1 计算x,y坐标和色域与实测数据进行比较 从表1看出,测量值和计算值之间的误差很大,领导的绿色计算域不接近实际价值很好。为了得到更准确的结果,绿色领导模型使用一个真正的RSD curvedirectly,其峰值波长和半最大值是525 nm和40 nm),这是显示在图2。然后通过保留RSD曲线的形状,将峰 第 10 页 苏州大学本科生毕业设计(论文)附件:外文文献资料与中文翻译稿 值波长,我们使用了MATLAB计算x,y坐标的绿色发光二极管:525海里,(0.2004,0.7138);515海里(0.1469,0.6800)。因此,计算域的选项卡。1 NTSC分别NTSC和114.0%变化到118.6%,几乎相当于测量范围。 图2 RSD真实绿色led曲线 从上面的RGB RSD模型三基色 LED背光的颜色范围可以遵循: gamunt,gamunt(,,,,,) r0g0bo (7) ,,,,,分别是红绿蓝 led的峰值波长。 g0r0b0 3. 模拟和分析 LED背光设计时,必须考虑其亮度的颜色范围。最近,领导的照明效率仍然很低,其亮度随波长。所以峰值波长的三个基本的适当范围选择led灯:红色发光二极管620 nm - 650 nm), 绿色的510 nm - 530 nm和450 nm - 450 nm,蓝色的。基于RSD led的三种模型,我们计算和分析了三种基本颜色的组合,其峰值波长在上面的范围中,研究ofcolor域和峰值波长的关系三种基本颜色。当绿灯的峰值波长为521 nm(相应的主波长大约528海里),three-basic-color背光的颜色范围达到最大。和色饱和度增加单调的红光波长峰值增加,当这些绿色和蓝色灯保持不变,但随着蓝光峰值波长的增加而单调减小当绿色和红色的灯光保持不变。此外,我们发现,峰值波长的组合(650 nm、521 nm、650 nm)是最佳,NTSC及其颜色范围可以达到120%以上。显示在图3。 第 11 页 苏州大学本科生毕业设计(论文)附件:外文文献资料与中文翻译稿 图3红绿蓝各自波长和色饱和度的关系 而且,三种颜色的组合全体115% NTSC和110% NTSC绘制的图片,显示在图4和图5分别 图4三种颜色的组合NTSC范围的115% 第 12 页 苏州大学本科生毕业设计(论文)附件:外文文献资料与中文翻译稿 图5三种颜色的组合NTSC范围的110% 4. 结论 本文建立了RGB led的相对光谱分布模型。通过模拟模型、关系三种基本颜色LED背光的颜色范围随每种颜色进行了分析,并得到最佳的三种颜色组合在给定的波长范围。此外,三种颜色的组合NTSC绘制NTSC的115%和115%,分别,那些照片可能提供了一个直观的指导,选择合适的三色的组合。 第 13 页