【作者】 喻春雨；

【导师】 常本康；

【作者基本信息】 南京理工大学 ， 光学工程， 2006， 博士

【摘要】 在过去的一个世纪里，X射线成像技术经历了胶片—增感屏成像技术、影像增强器成像技术、计算机X射线成像技术、平板探测器成像技术和计算机层析扫描技术的历史发展过程，它在医学、检测和工业探伤等方面是功不可没的。 在实时数字化的平片成像方面，国外近年来推出平板探测器成像技术，它具有视野大、成像性能好的优点，但是其价格昂贵，我国很少进口；我国较多进口法国和日本的X射线影像增强器来组装医用X射线成像机。它的价格也较高，成像视野不易制得很大，而且任一部分出现问题会使整管报废。因此，需要研制一种大视野、高质量、低成本的X射线影像探测器。 基于我国对一种新型X射线影像探测器的需求和南京市科技局的《用于防恐安检的12″新型X射线影像增强器的研制》项目和江苏省科技厅的《具有可移动数字化X射线成像机》项目，本文设计了新型的X射线影像探测器并研制了X射线成像系统，其研究的主要内容如下： 第一章主要介绍了X射线成像技术的原理及发展背景和本文研究的背景及意义。 第二章详细介绍了本文X射线成像系统的设计思想和系统组成及设计理论。设计的重点是新型X射线影像探测器。建立了分辨率数学模型并对新型X射线影像探测器成像性能进行了理论分析；研究了探测器的组成器件之间的光谱匹配情况，对有效的利用光能起到重要的指导作用，从而提高图像质量；提出了X射线成像系统视频接收器件的分辨率所应达到的标准，以保证图像不失真地输出终端。 第三章对本文设计的X射线成像系统的成像性能从图像对比度、分辨率、噪声三个方面进行了分析，分析的重点是图像分辨率。首先应用第二章建立的分辨率模型对系统的总分辨率进行了理论分析，找到了限制系统分辨率的瓶颈所在，并给出了解决的方法；应用调制传递函数对系统的成像性能进行了分析，并求得了系统调制传递函数曲线，分析结果和利用分辨率模型求得的结果相符；利用图像最佳放大倍数对系统的成像条件进行了分析，并结合变焦镜头，最大限度地降低几何模糊度，从而提高系统分辨率。 第四章应用数字图像处理知识并结合本文图像的特点，讨论了有效改善图像质量的方法，有助于做好图像的后处理工作。 第五章介绍了实时图像处理器的硬件设计和图像处理模块的设计。 第六章介绍了本文设计的机场足部安检X射线成像系统，并将其与军区医院的X射线成像系统在组成、成像性能、视野和价格等方面进行了详细的比较。结果说明：设计的成像系统性价比远远高于军区医院的成像系统，并满足大视野成像要求，成像质量达到透视检测标准。更多还原

【Abstract】 In the past century, x ray imaging technology was developed from film-screen imaging technology, x ray intensifier imaging technology, computer radiography to flat panel imaging technology and computer tomography, and it is of indelible merits in the fields of medical, nondestructive test, industrial detection and others.In the real time and digital x ray imaging technologies, the flat panel detector imaging technology appeared several years ago and was paid much attention because it has advantages of big visual field and high imaging performance, but it is too expensive for us to import freely. Now, the x-ray image intensifier is often used in the hospital and other x ray imaging application fields, and it is mainly imported from France and Japan because there is no manufacture in China. Compared with the cost of film-screen technology, the cost of the x ray image intensifier is high, and it is often discarded for any defect and its visual field was limited by the difficult production technique. For the analysis, the novel x ray image detector is in need, which must be of big visual field, high imaging performance and low cost for the usual users.Basing on the city science and technology bureau’s project of the manufacture of the 12 inch novel x ray image intensifier applied in the anti-terror security test and the province science and technology office’s project of the movable digital x ray imaging machine, this paper designed the novel x ray image detector and the x ray imaging system and the content of this dissertation is summarized as follows:Chapter one introduced the x ray imaging technology and its development mainly, and led to the background and the meaning of this dissertation.Chapter two introduced mainly the x ray imaging system’s design principles and its components’ characteristics which included the matching requirements for the spectral compatibility and the pixel number. The novel combined x ray image detector is the key device of the x ray imaging system and obviously, it is also the key content of this chapter. To analyze the imaging performance of this x ray image detector, a mathematic relation about the resolution was modeled. The spectral matching factors between the x ray intensifying screen and the photo cathode were calculated. The resolution requirement for video system, such as the CCD camera and displayer was given by some formulas. All these data are referential to the x ray system’ imaging performance and can reduce the information loss in the imaging course.Chapter three analyzed the x ray imaging system’s imaging performance in the image更多还原