共查询到20条相似文献,搜索用时 687 毫秒
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本文主要介绍LED的光通量和发光效率的测试原理、方法、步骤及系统实现,重点分析应用LabVIEW构建检测系统软件功能的实现,从而得到实验检测数据。 相似文献
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环境照度对手机亮度最优值的影响 总被引:2,自引:2,他引:0
环境照度和手机屏幕亮度是影响手机显示性能的两大影响因素。本文选取14个不同的环境照度水平对手机的亮度自动调节功能进行测试,根据测试结果选取24组有代表性的环境照度和手机亮度组合进行手机屏幕显示质量主观评测,在主观评测的基础上选取12组环境照度和手机亮度组合对手机屏幕的显示质量参数进行测量,并综合主观评测结果与质量参数测量结果分析得到最优的环境照度与手机亮度组合。主观实验结果表明:在环境照度不变的情况下,适当地提高手机的自动调节亮度能有效改善手机的显示效果;不同环境照度下的手机亮度最优值不同。显示质量参数测量实验表明:在环境照度不变的情况下,适当地提高手机的自动调节亮度后手机屏幕的亮度对比度、色彩饱和度及色域范围均有明显提升。 相似文献
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介绍了一种基于PIN光电二极管的紫外激光脉冲能量在线检测系统。首先,采用激光主光路外的检测光实现激光脉冲能量的无损在线响应;其次,采用高速高精度积分电路将响应光电流处理为电压峰值;最后,利用激光系统的同步触发信号进行检测时序设计从而获得精确的激光脉冲前后的检测系统输出差值,经过计算后获得精确的激光脉冲能量。检测系统在248 nmKrF和308 nmXeCl准分子激光器上进行了测试,实现了对0~200 Hz重复率运行的准分子激光能量在线无损检测,测量结果与输出端外置能量计测得结果相对比,相关性与可重复性一致,满足应用需求。 相似文献
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要精确处理LED显示屏的色度,必然涉及到显示屏色度坐标的转换问题,但现有的许多公式不够系统、方便,文章给出了方便实用的通用计算方法和公式,由此可以方便地编写成程序,从而实现各个显示屏的色度系统之间以及它们与CIE、NTSC、PAL系统之间方便的色度转换。 相似文献
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《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1973,61(7):1007-1013
Projection display systems which use a scanned infra-red laser beam to thermally record graphic information on different media may offer a useful alternative to CRT and other display systems. Three different types of thermal-recording projection display systems are reviewed. Laser micromachining of thin bismuth film has proved to be a very simple and efficient way to obtain instant high-quality images which are also permanent. Variable amplitude light pulses produced by an intracavity modulated laser beam were used to write these images. With an average laser power of 20 mW, 8×10 mm2facsimile type continuous-tone images, with a resolution of 1300×2000 resolvable elements, were recorded in 4 s. Thermal writing on liquid crystals offers a unique and simple way to record and display high-quality high-resolution graphic images with the capabilities of fast total or local erase. A CW Nd:YA1G laser was used to write graphic and alphanumeric-type information on cholesteric and smectic-type liquid-crystal light valves. High quality black and white images with a resolution of 2000×2000 picture elements were recorded within 30×30 mm2of liquid-crystal cell frames. With 4 mW of laser power, images were recorded at a rate of 104resolvable elements per second. A contrast ratio of 7:1 was obtained with the cholesteric-type liquid-crystal light valve. The stored image was electrically erased in about 0.1 s. In smectic-type light valves, the contrast ratio was better than 10:1 and local erase was achieved by the application of an electric field while the laser beam locally heated the erased area. 相似文献
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激光的强相干性造成了激光投影显示中出现大量干涉条纹和散斑,为了消除干涉条纹和散斑对图像质量的影响,采用旋转新型散射体(Engineered DiffuserTM)的方法在一定积分时间内获得叠加的清晰图像。首先,介绍了激光投影显示中散斑的成因及采用时间平均抑制散斑的理论依据。接着,分析了传统散射体毛玻璃和Engineered DiffuserTM在结构及功能上的区别。最后,建立了旋转新型散射体抑制散斑的激光投影显示实验装置,对比验证了旋转新型散射体抑制散斑的效果。实验结果表明:散斑对比度降低到3.08%,图像质量良好,无明显干涉条纹。该方法满足商用激光投影显示体积小、简单易行等要求。 相似文献
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投影电视的均匀照明系统设计 总被引:1,自引:0,他引:1
分析和设计了用于提高大屏幕投影电视光学性能的均匀照明系统:透镜阵列和积分方棒。基于弧长为1.2mm的超高压水银灯(UHP).建立嵌套圆筒的体光源模型.给出了两个照明系统的设计方法和用于2.3cm空间光调制器照明系统的设计参数。仿真结果表明,透镜阵列系统实现了均匀性( 4.55%,-5.54%),光能利用率为81%的照明输出;积分方棒系统实现了均匀性( 4.37%,-4.58%),光能利用率为79%的远心照明输出。均能满足投影电视对照明系统的指标要求。 相似文献
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Performance of High Power Light Emitting Diodes in Display Illumination Applications 总被引:1,自引:0,他引:1
The performance of liquid crystal displays and micro display projection systems is for a large part determined by the lamps and illumination optics they are using. Traditionally, gas discharge lamps are used, but light-emitting diode lamps are gradually taking over because of their attractive characteristics. We will discuss how the transfer to light-emitting diodes in the various display architectures changes the key performance parameters, remaining technical challenges, and prospects for future improvement 相似文献
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Chun-da Liao Jui-che Tsai 《Industrial Electronics, IEEE Transactions on》2009,56(4):1057-1065
Due to the advancement of microoptoelectromechanical systems and microelectromechanical systems (MEMS) technologies, novel display architectures have emerged. One of the most successful and well-known examples is the Digital Micromirror Device from Texas Instruments, a 2-D array of bistable MEMS mirrors, which function as spatial light modulators for the projection display. This concept of employing an array of modulators is also seen in the grating light valve and the interferometric modulator display, where the modulation mechanism is based on optical diffraction and interference, respectively. Along with this trend comes the laser scanning display, which requires a single scanning device with a large scan angle and a high scan frequency. A special example in this category is the retinal scanning display, which is a head-up wearable module that laser-scans the image directly onto the retina. MEMS technologies are also found in other display-related research, such as stereoscopic (3-D) displays and plastic thin-film displays. 相似文献
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虚拟激光投影在动态交互时,易用性差、鲁棒性低都会导致交互方法的交互性能变差,为提高激光投影交互效果,提出基于视景仿真技术的虚拟激光投影动态交互方法。利用VEW方法采集激光投影视频图像,利用加权平均法对采集到的视频图像背景去噪,并基于红绿蓝三原色建立视频的RGB彩色空间模型,对背景去噪后的图像灰度转换后,进行阈值分割;依据预处理结果确定激光投影中心点位置,通过投影的中心点映射,实现投影动态交互;使用视景仿真技术对交互场景图像的交互效果实施增强,提高激光投影的动态交互性能。实验结果表明,运用该方法开展激光投影动态交互时,交互性高、易用性好、鲁棒性高。 相似文献
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以非成像理论中光学扩展量的传递规律为依据,给出了激光二极管(LD)阵列作为光源的新型激光投影显示系统中方棒照明光路元器件尺寸及入射光束孔径角的确定方法。选用3×8红光LD阵列作为光源,0.45inch(1inch=25.4mm)硅基液晶(LCOS)芯片为空间光调制器(SLM),应用光学设计软件Zemax给出了方棒照明系统的设计实例,包括LD阵列光源光束整形系统、方棒匀光系统、方棒中继系统的设计。结果显示方棒照明系统具有较高的光能利用率及较好的光斑均匀性。由此得出较高光能传递质量的新型激光投影显示系统中方棒照明系统的设计方法。 相似文献