Design And Realization Of The Automatic Regulating System Of Electron Microscopy Filament

Electron microscopy referred to as electron microscopy, is based on the principle of electronic optics, with electron beams and electron lenses instead of beams and optical lenses, so that the fine structure of the material in a very high magnification imaging equipment. Electron microscopy as a powerful tool for microscopic observation of the surface,is increasingly rapid and widely used in metallurgy, mineral, chemical,pharmaceutical, biological, food, nano-materials and other fields. The electron beam of the electron microscope is produced by an electron gun,and the filament is used in the electron gun. At present, most of the tungsten wire is used. The life of tungsten filament is relatively short,so the filament replacement becomes very frequent.Electron microscope filament in the replacement process mainly by the staff of the use of external hexagonal screw in the microscope under the manual adjustment, there is no fixed steps, only by virtue of the experience of the operator. And the filament alignment results, only by virtue of the operator eye observation, the accuracy is difficult to guarantee, thus affecting the performance of electron microscopy and greatly reduce the filament life.In order to further improve the efficiency and accuracy of the filament alignment, a system for automatically identifying and adjusting the filament position is required. First of all, the paper designed a mechanical platform, responsible for carrying the entire system operation,positioning and fixed electric filament base, according to the adjustment of precision to select the appropriate stepper motor, and the motor rotation through the transmission device into the filament displacement.Secondly, the secondary development of the image detection equipment is carried out, the image gray scale processing of the weighted average method is increased, the image filtering process of the Gaussian filter is applied, the edge is extracted by the Canny operator, and then the Hough algorithm is used to realize the circle Hole recognition, summed up the filament center recognition algorithm, so that the filament position to achieve automatic detection and identification. Finally, the Arduino Mega 2560 controller hardware platform is built to realize the precise control of the stepper motor. The host computer software is written in the LabVIEW environment to realize the communication with the Arduino controller.Through a set of control algorithms, the host computer software can realize the automatic control of the stepping motor, and finally realize the goal of automatic detection, recognition and adjustment of the position of the electric filament.The system has a wide applicability for the vast majority of electron microscopy and improves the working efficiency of the electron microscope operator. The system can realize the automatic adjustment and positioning in the process of electron microscope filament replacement.