共查询到19条相似文献,搜索用时 46 毫秒
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在传统的纯相位全息显示系统中, 一般基于快速傅里叶变换(FFT)算法来计算相位全息图, 在FFT的计算中需要遵循Nyquist采样定理, 因此, 重建图像的尺寸往往受限于空间光调制器的固定采样率. 这个限制可以通过卷积算法或者两步菲涅耳衍射算法来解决, 但是需要使用多个FFT的计算, 导致计算量增大. 鉴于此, 提出了一种基于透镜的纯相位全息图计算方法. 在全息图的计算中, 通过透镜的成像原理建立一个采样率可变的虚拟全息面, 通过调节相应的距离参数使得在全息图的计算中可以任意调节原始图像的采样率, 摆脱了传统方法中液晶空间光调制器带宽积对重建图像尺寸的限制, 并且这种算法只需使用一次FFT就能达到变采样率的衍射计算, 大幅提高了全息图的计算速度. 数值模拟及光学实验结果证明了此方法可以在全息显示光学系统中清晰地重建不同尺寸的图像. 同时该系统可以有效地消除由空间光调制器的像素化结构带来的零级衍射. 相似文献
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In this paper a novel method is proposed to determine the cell parameters including the twist angle, optic retardation and rubbing direction of twisted-nematic liquid crystal displays (TNLCD) by rotating the TNLCD. It is a single-wavelength method. Because using subtraction equation of transmittance as curve fitting equation, the influence of the light from environment and the absorption by polarizer, the sample of TNLCD and analyser on the transmittance is eliminated. Accurate results can also be obtained in imperfect darkness. By large numbers of experiments, we found that not only the experimental setup is quite simple and can be easily adopted to be carried out, but also the results are accurate. 相似文献
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Low voltage transflective blue-phase liquid crystal display with a non-uniform etching substrate 下载免费PDF全文
A transflective polymer-stabilized blue-phase liquid crystal display(BP-LCD) with a non-uniform etching substrate is proposed.In-plane switching(IPS) electrodes on the bottom substrate are put on the different gaps,and the bottom substrate between the electrodes is etched into different depths in transmissive(T) and reflective(R) regions.This structure can balance the optical phase retardation in the two regions and is helpful to achieve well-matched voltag-dependent transmittance and reflectance curves.This transflective display has high optical efficiency,a wide viewing angle,and low operating voltage(approximately 6 V). 相似文献
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A quantified focal plane testing method, termed phase-shifting grating-slit test, is demonstrated by utilizing a micro liquid
crystal display. In contrast to the setup in the Ronchi Test, an incoherent illuminating grating is used and an optical slit
is located at the image plane of the tested lens to modulate the aberrated wavefront. With the micro liquid crystal display
generating and phase shifting the incoherent illuminating grating with variable frequency, a higher measurement dynamic range
can be achieved on demand. 相似文献
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随着近几年液晶显示技术在诸多领域的广泛应用和新技术的推出,人们一直致力于改善液晶器件显示性能的研究。在液晶显示器应用中,电光特性是一个很重要的参数,介绍了采用激光测量的方法获得液晶的电光特性、阈值电压及视角特性。分析了液晶分子在交流电场作用下重新取向后的扭曲特性,测试了不同电压下液晶分子的透光率和扭曲角度,结果表明:该方法是可行的,向列相液晶具有0.92 V较低阈值电压和较为陡峭的电光曲线,水平方向上在-60~+50有较好的视角特性,垂直方向上在-40~+20有较好的视角特性。该结论为偏光器件的设计与制作提供了依据。 相似文献
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Mathematical model of light propagation through liquid crystal display working under real conditions
M. Olifierczuk 《Opto-Electronics Review》2008,16(3):287-296
The main aim of our work is to present a theory of light propagation through a liquid crystal display worked out in our University.
This theory takes into account real conditions of a display operation such as temporal coherence of light source, interference
phenomena, spectral characteristics of refractive coefficients of individual layers and their complex forms, real directions
of ordinary and extraordinary wavevectors into each layer, real directions of light polarization into anisotropic or dichroic
layers etc. Therefore, our theory can be used to determine optical parameters of a liquid crystal display operating under
real or at least quasi-real conditions. Contrary to other theories (e.g., Beremann or geometric optics approximation), this
model is characterized by a small number of simplifications. Thus, it can be used to analyse a display operating in special
conditions, such as military or out-door applications. In these cases, very high optical parameters (luminance and contrast
ratio) aare needed. Application of even small simplifications conducts to significant changes of calculated parameters. 相似文献
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A novel see-through display with a liquid crystal lens array was proposed.A liquid crystal Fresnel lens display(LCFLD) with a holographic screen was demonstrated.The proposed display system has high efficiency,simple fabrication,and low manufacturing cost due to the absence of a polarizer and color filter. 相似文献
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利用光导纤维与CRT相结合的技术,产生高清晰度图像字符信息启动液晶光阀,在外光源的照射下,投影得到高清晰度、高亮度图像。 相似文献