BAI Jiang-hua
（Department of Physics, Portland State University, Portland, OR 97201, USA）
Abstract：In this work, an old scanning electron microscope (SEM) is refurbished to enhance its image processing capability. How to digitally sample and process an analog image is also presented. An NI PCI-6259 multiple input/output data acquisition (DAQ) board is used to acquire signals originally being sent to an analog display, and then convert the signals into a digital image. Two output channels are used for raster scan of the horizontal and verticle axes of the image buffer, while one input channel is used to read the brightness signals at various coordinate points. Synchronous method is used to maximize the DAQ speed. Finally, the digitally buffered images are read out to display and saved in a hard drive. The hardware and software designs of this work are explained in great detail, which can serve as a very good example for fast synchronous DAQ, advanced virtual instrument design and structural driver programming with LabVIEW.
Key words：scanning electron microscope; analog image display; raster scan; synchronous data acquisiotion (DAQ); LabVIEW
CLD number：TN911.73; TN16 Document code：A
Article ID：1674-8042（2019）04-0329-06 doi：10.3969/j.issn.1674-8042.2019.04.004
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用同步数据采集法读取电子显微镜的模拟图像
白江华
（波特兰州立大学 物理系， 波特兰 97201， 美国）
摘 要: 本项目对老式电子显微镜翻新， 使其拥有强大的图像处理能力， 同时还介绍了模拟图像的数字化采集和处理的方法。 将NI PCI-6259多用途数据采集卡与电子显微镜的模拟显示电路相连， 把原来用光栅扫描法传送到模拟显示器的信号输入到PCI-6259的数据缓冲区中； 2路输出通道分别扫描显示电路的横纵坐标， 1路输入通道采集各坐标点的亮度信号， 数据采集卡的2路输出通道与1路输入通道工作在同步方式下， 以实现对模拟图像的最快速数字采集。 数字图像采集之后， 就立即显示并自动存储在硬盘中。 文章详细描述了硬件连接与软件设计， 是快速同步数据采集、 虚拟仪器的高级应用和用LabVIEW结构化地设计底层驱动程序的良好范例。
关键词: 扫描电子显微镜； 模拟图像显示； 光栅扫描； 同步数据采集； LabVIEW
引用格式： BAI Jiang-hua. Retrieving analog images from a scanning electron microscope with a synchronous data acquisition method. Journal of Measurement Science and Instrumentation, 2019, 10（4）： 329-334. ［doi： 10.3969／j.issn.1674-8042.2019.04.004］
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