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用于微光摄像的高灵敏度电子轰击电荷耦器件 总被引:10,自引:0,他引:10
文章综述微光成像的电子轰击电荷耦合器件(EBCCD)的进展。EBCCD是将像管的荧光屏以对电子灵敏的背照明、减薄CCD代替,将电子图像直接转变为视频信号,其在所有光照等级下,特别是在极低微光下的调制传递函数(MTF)、分辨力、信噪比、余辉等均优于像增强器耦合CCD(ICCD)。文中较为详细地叙述了倒像式EBCCD设计与减薄工艺,给出各种类型倒像式EBCCD像管的技术参数,分析和比较了近贴式与倒像式EBCCD与ICCD的性能,指出了EBCCD在军用夜视技术与民用技术未来发展中的地位与重要性。 相似文献
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三代微光器件的测试和评估技术研究 总被引:1,自引:0,他引:1
在已有的负电子亲和势(NEA)光电阴极特性评估技术的基础上,研制了三代微光器件的测试和评估系统工程样机,用于对三代微光器件的光谱响应等参数的测试和激活过程中的工艺信息监控,通过分析计算可获得三代微光器件光电阴极的表面逸出几率、载流子扩散长度和后界面复合速率等参数.利用该系统对三代微光像增强器进行了测试和评估,文中给出了测试结果并加以分析. 相似文献
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介绍了运用蒙特卡罗方法分析三代微光像增强器分辨率的方法。该方法取一组随机数,来模拟像管中光电阴极受激发射的电子。综合考虑微通道板参数、第一近贴距、第二近贴距、阴极电压和荧光屏电压等影响,模拟追踪电子的运动轨迹。并根据像面上电子的落点分布来计算调制传递函数,从而确定像管的分辨率。经比较,此方法计算简单、运行快速,模拟结果与实验值的偏差不超过5%,理论模型满足实际需求,可为三代微光像增强器的设计提供参考。 相似文献
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就像蛇利用它们敏感的热成像系统捕获猎物一样,越来越多的维修工人在热成像摄像仪的帮助下发现了许许多多隐藏的问题。让我们一起来通过测试了解一下这些热成像摄像仪有什么不同,它们又是怎样进行测试的。 相似文献
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染料热转移成像材料及其在印刷领域中的应用 总被引:2,自引:2,他引:0
本文叙述了染料热转移成像材料的类型,特点和成像原理以及它倦印刷领域中的应用,比较了熔融型和升华型材料的印刷特性的印刷质量,介绍了几种利用染料热转移的直接印刷和直接制版体系。 相似文献
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利用自行研制的“光电阴极多信息量测试系统”首次对国产三代微光管中的GaAs光电阴极的均匀性进行了光谱响应测试 ,结果表明该国产三代微光管存在明显的非均匀性。利用曲线拟合方法估算了GaAs光电阴极的材料性能参数 ,发现表面逸出概率不一致是非均匀性的主要原因 ,GaAs材料的少子扩散长度 (1 1 2~ 1 82 ) μm ,与阴极厚度相当 ,后界面复合速率在 (1× 1 0 5~ 1× 1 0 6 )cm/s之间 ,它限制了阴极灵敏度的提高 相似文献
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针对靶场传统高速摄影存在局限性,随着光电成像技术的发展及高速电视摄像在靶场应用研究的不断深入,从高速电视摄像系统的构成出发阐述其基本工作原理及主要特点。与高速摄影进行对比,介绍了高速电视摄像系统在靶场光学测量系统中的应用,其替代靶场传统的胶片式高速摄影系统,担负着获取场区设备及工作人员的安全控制信息源的重要任务。 相似文献
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This study proposes an improved method which employs the shaped-function technology and Discrete Fourier Series Transform (DFST)-based algorithm to improve the subjective impression at low light level. A sinusoidal wave light signal which is generated in the low frequency range plays the role of a shaped-function signal. The basic procedure of the proposed method is that an LED with a time-varying (sinusoidal) beam is used to illuminate the image sensor evenly. Then, a DFST-based algorithm is employed to remove the sinusoidal wave signal from the captured images for restoring the low-light-level image signal with a low gray resolution. The main purpose of this method was to improve gray-level resolution and signal-to-noise ratio of the acquired image and process the image data in real time by sliding the window. The derivation processes and experiments verify that the improved method not only can reveal a better result than the algorithms we have proposed before, but also have a better performance on the imaging speed. 相似文献
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An improved approach for design of the catadioptric omnidirectional camera with horizontal scene undistorted imaging is described. In the proposed approach, the influence of the lens distortion on the imaging quality of the omnidirectional camera is taken into account. We establish a radial distortion model for an image pickup lens and retain some opposite distortion in the mirror to correct the distortion existing in the image pickup lens. A horizontal scene undistorted catadioptric omnidirectional camera is designed with an off-the-shelf TV short focus lens using our approach; the numerical simulation shows that the distortion introduced by the imaging lens is eliminated effectively. 相似文献
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New types of lens-less two-photon ghost imaging experiments are described that can also be useful for 3D X-ray imaging. In these experimental setups, a CCD array is placed facing a chaotic light source and gated by a photon counting detector that simply counts all randomly reflected photons from an object. A “ghost” image of the object is then observed from the gated CCD. A ghost image of an object can even be observed when the photon path to the photon counting device is obscured. These interesting demonstrations are not only useful for practical applications, such as X-ray lens-less imaging, but are also important from a fundamental point of view. These demonstrations lead to insight regarding the nonclassical two-photon interference nature of thermal light ghost imaging. 相似文献
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医疗数字X射线成像及其发展趋势——与医用胶片相关的问题 总被引:1,自引:1,他引:0
本文概述医疗数字x射线概况及发展趋势。与传统屏片成像相比,数字x射线成像系统有许多优点,包括:射线计量小、图像信息量大、提高诊断质量、减少重拍、影像可通过网络传输、减少冲洗加工污染等,因此得到广泛应用,迅速发展。据统计,2008年全球图像管理与通信系统(PACS)采用率已达64%,几家著名影像工业公司都大力开发数字医疗射线成像相关产品,本文详加介绍。我国的医疗数字X射线成像也在迅速发展,但由于种种原因,完全取代传统的屏片成像还需要较长时间。 相似文献
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中华医学会影像技术分会第15次全国学术大会于2007年10月在上海召开,与会代表近600人,发表论文800余篇,内容涵盖医学影像技术的各个领域,如:数字成像,CT成像,MR成像,医学工程、影像质量控制和管理等等。大会主题是:医学影像数字化技术和图像后处理。本文据此提出几个有关当前医学影像发展需要特别关注的问题。 相似文献
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显微热成像系统行处理迭代超分辨力处理研究 总被引:1,自引:0,他引:1
针对已研制光学微扫描显微热成像系统空间分辨力较低的问题,基于改进的频域图像配准技术和改进的行处理迭代超分辨力算法,提出了显微热成像系统光学微扫描改进行处理迭代超分辨力图像处理方法。给出了该方法的原理及步骤,采用不同重构方法针对可见光和红外图像进行了仿真研究,给出了评价参数和结论。利用光学微扫描显微热成像系统采集低分辨力显微热图像序列进行了超分辨力处理实验,实验结果表明本文提出方法的有效性,光学微扫描显微热成像系统的空间分辨力得到提高,可应用于需要显微热分析的场合。该方法还可以应用于其它不可控光学微扫描成像系统中,具有广泛的应用前景。 相似文献
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星体目标自适应光学成象补偿 总被引:1,自引:0,他引:1
大气湍流等动态波前扰动限制大型望远镜的分辨能力,是从有望远镜以来几百年的老问题,自适应学技术提供了解这一问题的途径。但对星体目标来说由于所能利用的光能极为有限,动态扰动的时间-空间特性又对系统提出很高要求,因而难度很大。本文报导我们用21单元自适应光学系统在云南天文台1.2m望远镜上对星体目标进行的首次试验。介绍了针对弱光动态目标的特点对系统的改进。实验结果表明了这一自适应光学系统可以在光子计数率 相似文献
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M. Vielreicher S. Schürmann R. Detsch M. A. Schmidt A. Buttgereit A. Boccaccini O. Friedrich 《Journal of the Royal Society Interface》2013,10(86)
This review focuses on modern nonlinear optical microscopy (NLOM) methods that are increasingly being used in the field of tissue engineering (TE) to image tissue non-invasively and without labelling in depths unreached by conventional microscopy techniques. With NLOM techniques, biomaterial matrices, cultured cells and their produced extracellular matrix may be visualized with high resolution. After introducing classical imaging methodologies such as µCT, MRI, optical coherence tomography, electron microscopy and conventional microscopy two-photon fluorescence (2-PF) and second harmonic generation (SHG) imaging are described in detail (principle, power, limitations) together with their most widely used TE applications. Besides our own cell encapsulation, cell printing and collagen scaffolding systems and their NLOM imaging the most current research articles will be reviewed. These cover imaging of autofluorescence and fluorescence-labelled tissue and biomaterial structures, SHG-based quantitative morphometry of collagen I and other proteins, imaging of vascularization and online monitoring techniques in TE. Finally, some insight is given into state-of-the-art three-photon-based imaging methods (e.g. coherent anti-Stokes Raman scattering, third harmonic generation). This review provides an overview of the powerful and constantly evolving field of multiphoton microscopy, which is a powerful and indispensable tool for the development of artificial tissues in regenerative medicine and which is likely to gain importance also as a means for general diagnostic medical imaging. 相似文献