新型数字显示设备基础知识(五)

九、决定画质的要素关键词:亮度、层次和色彩数、对比度、精细度、分辨率、像素数、色再现范围、伽玛特性基本概念:亮度:指显示板和背光灯的亮度,单位为cd/m2,也叫nit(尼特)。国家信息产业部推荐的数宇电视设备25项标准中,电视显示器有用平均亮度标准为:CRT显示器≥60 cd／m2;液晶电视≥     

投影显示对美术馆参观者视觉舒适度影响的实验研究

搭建了美术馆实验环境,被观赏画作表面的照度为200 lx,采用LED光源的色温为3 300 K.改变投影仪的亮度和对比度参数,设定三种常用投影显示模式(模式1-亮度24.7 cd/m2,对比度12:1;模式2-亮度57.7 cd/m2,对比度20:1;模式3-亮度78.9 cd/m2,对比度24:1),分别对32名实验...     

高亮度顶发射单色绿光OLED微显示器件制备

通过采用高效磷光体系材料和顶发射有机发光结构,配合自有的SVGA060全数字信号电路系统架构CMOS硅基驱动电路,获得了发光峰位于535 nm的高亮度单色绿光、0.6英寸、800×600分辨率OLED微显示器件,最大亮度可达20000 cd/m~2。其起亮电压为2.6 V,亮度从20 cd/m~2到20000 cd/m~2的驱动电压摆幅为2.7 V,最大电流效率为24.43 cd/A。电流密度为20 m A/cm~2时,色坐标CIEX=0.286、CIEY=0.665。该器件在1000 cd/m~2和500 cd/m~2亮度下的半衰期为42559 h和186208 h。     

Novaled高效白光OLED寿命达到10万小时

基于自有的PIN OLED(R)技术和材料,Novaled公司的照明用白光OLED性能又获重大提高:在亮度为1000cd/m2下效率达到35lm/W、寿命达到100000h,CIE坐标为(0.43,0.44),显色指数为90;而其在亮度为4000cd/m2时光效为31lm/W,色标及显色指数值则无明显变化。     

某型液晶显示器夜间亮度变化不均匀现象的分析与改进

某型液晶显示器夜间亮度变化不均匀,造成用户暗环境下对信息观察不准确。本文针对上述问题,结合设计方案进行问题分析并进行改进。即以每一档每一级的PWM输出实际测试值为基准,进行参数调整,保证了每一级的输出符合亮度指标要求。通过本解决方案,当亮度数据为9时,实测亮度为0.787 5cd/m~2,满足指标0.726～0.921cd/m~2的要求。亮度数据0与9间的亮度实测值变化量由1.124cd/m~2改进为0.712 55cd/m~2,9与18间的亮度实测值变化量由0.246cd/m2改进为0.772 5cd/m~2。每档之间的亮度实测值变化量相近,变化均匀,改善了显示效果,满足了用户的要求。     

磷光与荧光相结合的有机白光器件

首先制备了结构为ITO/m-MTDATA(30 nm)/NPB(20 nm)/CBP:FIrPIC(10%,30 nm)/5,6,11,12-tetraphenylnaphthacene(rubrene)(x nm/Bphen(40 nm)/LiF(0.8 nm)/Al的器件.此器件效率降低,为提高效率,我们又制备了另一器件,其结构为ITO/m-MTDATA(30 nm)/NPB(20 nm)/rubrene(0.2 nm)/CBP:FIrPIC(10%,30 nm)/Bphen(40 nm)/LiF(0.8 nm)/Al.此器件亮度效率及色坐标均有所改善.此器件的最大亮度为14 V时,10050 cd/m2,最大效率为8V时,4.59(cd/A),7 V时,1.89(lm/w).1000 cd/m2时的效率约为4.00 cd/A(10 V时,1.25 lm/w).当亮度由1354 cd/m2变到10050cd/m2时,色坐标由(0.33,0.37)变到(0.34,0.37).     

彩色有机薄膜电致发光器件及显示技术

对性能稳定的彩色薄膜有机EL器件进行了研究.其中绿色有机器件的半亮度寿命为14000小时(初始亮度100cd/m2),已达到实用化的要求.红色、蓝色和白色器件的半亮度寿命(初始亮度100cd/m2)分别达到了3750、1016和2850小时.在得到稳定的绿色有机薄膜电致发光器件基础上,对矩阵显示屏及动态显示技术进行了研究.得到了面积为48mm×30mm、分辨率为2线/mm的96×60象素矩阵显示器,其中单位象素的有效发光面积为0.4mm×0.4mm,单元间隙为0.1mm.并设计了有效的驱动和控制电路,实现了无"交叉效应"的、高清晰度的动态图形显示.显示器在1/64的驱动占空比下的显示亮度大于100 cd/m2,屏的功耗为0.6W.     

等离子体显示板面光源的制备技术及光电特性研究

利用等离子体显示板自发光、薄型、亮度高、发光均匀的特点,开发出基于等离子体显示机理的薄型等离子体面光源,用于需要薄型照明的特定场合.为克服等离子体显示板发光效率过低的不足,对面光源显示板的结构、材料,工艺和驱动电路诸方面进行多项改进,经改进后的等离子体面光源最小厚度不大于4 mm,亮度350 cd/m2,色温为 6500 K,发光效率4Lm/W.光源型 PDP 显示板的研究结果对进一步提高图象型 PDP 显示板的光电性能提供了有益的启示.     

平视显示器数字像源设计

设计了一款分辨率为1280×1024的TFT-LCD数字像源。利用专门的单色TFT-LCD, 采用高亮度绿色LED作为背光, 设计了基于可编程逻辑器件FPGA控制驱动系统的数字像源, 实现了DVI视频输入显示、Gamma校正、宽范围调亮和液晶屏低温自动加热功能, 最高亮度为30000 cd/m2, 最低亮度小于0.2 cd/m2, 调亮级数超过60000级, 工作温度范围-45°Ｃ～+60°Ｃ。     

可印刷磷光有机发光器件

本文报道了一种制造全色可印刷磷光有机发光器件的新方法,与传统加工0LEDs的方法不同,本可印刷磷光OLED有机发光器件的发射层中具有共轭聚合物,该发射层是由小分子基质与掺杂物组成的,本文给出的红、绿、浅蓝、蓝可印刷磷光OLED有机发光器件在初始亮度分别为500cd／m2、1000cd／m2、500cd／m2及500cd／m2时,其光效及预期寿命分别为9cd／A与5．3万小时,35cd／A与5．2万小时,18cd／A与3000小时,6cd／A与1000小时。     

YAG荧光屏的制作与性能

介绍一种YAG荧光屏的结构、制作以及性能。YAG荧光屏不同于传统玻璃荧光屏的一个显著特点就是以具有高热导率、高机械强度、良好绝缘性和透光性的单晶YAG代替玻璃作为荧光屏粉层衬底。我们在YAG衬底上采用离心沉淀法制作荧光粉层;有机膜采用手工旋涂法工艺制作;铝膜采用真空电阻蒸发法制作,并讨论了铝膜的最佳厚度选取。3英寸红、绿、蓝荧光屏在0.5mA电流、29kV电压下亮度分别是6.2×10     

Great improvement of operation-lifetime for all-solution OLEDs with mixed hosts by blade coating

We investigated some effective device designs and fabrication methods for long operation-lifetime all-solution-processed Phosphorescent OLEDs (PhOLEDs) and fluorescent OLEDs with mixed-hosts system and thin Poly [(9, 9-dioctylfluorenyl-2, 7-diyl)-co-(4, 4′-(N-(4-sec-butylphenyl) diphenylamine)] (TFB). The all-solution-processed green PhOLEDs had high current efficiency (30.3 cd/A) and long operation-lifetime. The best half-lifetime of green PhOLEDs with thin HTL, MH-hosts EML and optimized deposition was 310 h at an initial luminance 1000 cd/m², 250 h at an initial luminance 500 cd/m² for green PhOLEDs with thin HTL, and MH-hosts EML, and the lifetime of triple layer PhOLEDs device was only 0.5 h for the same materials. The red PhOLEDs exhibited a high current efficiency (10.93 cd/A) and half-lifetime with 157.9 h at an initial luminance 500 cd/m². For the blue fluorescent OLEDs, the thin polymer TFB, mixed-hosts EML, double EMLs and optimization deposition yield a high current efficiency (5.68 cd/A) and long operation-lifetime with 117.7 h at an initial luminance 500 cd/m². Single host fluorescent device had half-lifetime of 73.5 h only at an initial luminance 100 cd/m². Finally, by doping red emitter Rubrene into stable blue device, we achieved soft yellow OLEDs with high efficiency (10.87 cd/A) and 8 fold improvement operation-lifetime (1200 h). We believe that such all-solution-processed OLEDs which showed greatly improved operational lifetimes would be suitable for the indoor supportive lighting with natural colors.     

High efficiency green phosphorescent top-emitting organic light-emitting diode with ultrathin non-doped emissive layer

Ultrathin non-doped emissive layer (EML) has been employed in green phosphorescent top-emitting organic light-emitting diodes (TOLEDs) to take full advantages of the cavity standing wave condition in a microcavity structure. Much higher out-coupling efficiency has been observed compared to conventional doped EML with relatively wide emission zone. A further investigation on dual ultrathin non-doped EMLs separated by a special bi-layer structure demonstrates better charge carrier balance and improved efficiency. The resulting device exhibits a high efficiency of 125.0 cd/A at a luminance of 1000 cd/m² and maintains to 110.9 cd/A at 10,000 cd/m².     

Improved efficiency roll-off at high brightness in simplified phosphorescent organic light emitting diodes with a crossfading-host

We report a high efficiency and low efficiency roll-off green phosphorescent organic light emitting diode using both hole- and electron-transporting host materials in a crossfading profile. To eliminate the energy barrier and reduce the charge carrier accumulation, the host materials are used as transporting layers as well, which also simplifies the device fabrication. It is found out that the recombination zone of gradient doping host sample is not only wider but also extended at high current density, which contributes to the suppressed efficiency roll-off at high luminance. An external quantum efficiency of 21.0% at 1000 cd/m² is obtained, and maintains to 19.3% at 10,000 cd/m².     

有机高亮度黄光发光二极管

用有机小分子制备的高亮度黄光电致发光器件,在１９Ｖ下器件亮度可达４００００ｃｄ／ｍ２,外量子效率达３．４％．     

Fabrication of large-scaled organic light emitting devices on the flexible substrates using low-pressure imprinting lithography

This paper demonstrates an approach to fabricate large-scaled (70 /spl times/70 mm) patterned organic light-emitting devices (ITO/CuPc/NPB/Alq3/LiF/Al) on the flexible polyethyleneterephthalate substrates using low-pressure imprinting lithography. The patterns of the pixel array were defined in crossed-strip style with anode patterned by imprinting techniques followed by wet chemical etching and cathode strips deposited using metal mask. The measured results were: The turn-on voltage of the device was 7.5 V; the luminous efficiency reached 1.13 lm/W (3.04 cd/A) at a luminance of 3.8 cd/m/sup 2/ and its maximum luminance was 2440 cd/m/sup 2/, which were comparable to the performances of the devices patterned by conventional photolithography.     

高效高亮度硅基顶发射有机电致发光器件的研制

以半透明超薄金属银作为阴极,紫外臭氧处理的厚金属银作为阳极,制备了高效率高亮度的黄光硅基顶发射有机发光器件。当电压为9V时,器件的最大电流效率为4.9cd/A,当电压为17V时,器件的亮度达到14 040cd/m2。通过增加掺杂浓度及阳极厚度对器件结构进一步优化后,器件性能显著提高,其电流效率在外加电压为10V时达到11cd/A,相应亮度为21 748cd/m2.顶发射器件中存在的微腔效应能有效提高器件的发光效率以及亮度,但是也会使器件的共振波长随着观察视角的增大而蓝移。由于采用合适的发光材料,本实验制备的器件的发光峰值在0°~75°视角范围内几乎没有变化。     

基于DSA-ph的高效率超薄层蓝色有机电致发光器件

讨论了基于蓝色荧光染料DSA-ph作为发光层的蓝色有机电致发光器件,器件结构为：ITO/2T-NATA/NPBX/DSA-ph（xnm）/TAZ/Bphen/LiF/Al。通过改变DSA-ph的超薄层厚度,相应器件的性能指标也有所不同。研究表明,在超薄层厚度为0.5nm,驱动电压为4V时,器件的最大发光效率为6.57cd/A;在超薄层厚度为0.3nm时,驱动电压为10V时,器件的最大亮度为5 122cd/m^2。器件的色坐标在（0.17,0.36）附近,属于蓝光发射。     

Highly efficient solution-processed small-molecule white organic light-emitting diodes

Solution-processed small-molecule white organic light-emitting diodes (WOLEDs) were fabricated with a co-host of hole-transporter 4,4′,4″-Tris(carbazol-9-yl)triphenylamine (TCTA) and electron-transporter 2,7-Bis(diphenylphosphoryl)-9,9'-spirobifluorene (SPPO13). By doping 15 wt% FIrpic or F₃Irpic and 0.5 wt% Ir(MDQ)₂(acac) in to the TCTA/SPPO13 host, highly efficient white OLEDs have been achieved which exhibit nearly identical emission spectra at different luminance. The F₃Irpic and Ir(MDQ)₂(acac)-based WOLED shows maximum efficiencies of 40.9 cd/A, 36.7 lm/W and 16.9%, and even high efficiencies of 30.1 cd/A and 12.3% at the practical luminance of 1000 cd/m², which are among the highest efficiencies of the solution-processed small-molecule WOLEDs. These results demonstrate a convenient way to realize solution-processed WOLEDs with high efficiency and high spectral stability through full small-molecule materials system.     

加入激子阻挡层增强白色有机发光器件效率

通过在发光层（EBL）与电子注入层之间增加激子阻挡层（EBL）制备了新型白色有机发光器件（WOLED）。有EBL的新型器件效率和亮度均比传统结构器件高50％,在电流密度为4mA／cm^2时效率达到3．42cd／A,最大亮度为11000cd／m^2（16V）,色坐标为x=0．34、y=0．36;而具有相同EBL厚度的传统结构器件,在电流密度为4mA／cm^2时效率为2．15cd／A,最大亮度为6259cd／m^2（16V）。效率的提高是由于EBL的限制作用而提高了激子浓度。测量了器件的效率与电流密度关系,随电流密度增加电流效率的衰减缓慢,说明短寿命红色搀杂剂的激子-激子湮灭很弱。