| 摘要 |
PROBLEM TO BE SOLVED: To realize a control method of an electron beam in a transmission type electron microscope which enables such a control that an electron beam can be focused in the optimal range irrespective of a photographing position. SOLUTION: A picture displayed on a fluorescent plate 10 is photographed by a TV camera 17. A picture signal from the TV camera 17 is supplied to a cathode-ray tube 20, therefore, the picture on the fluorescent plate 10 is displayed on the cathode- ray tube 20. An operator selects a range of a sample to be photographed and selects a control position of an electron beam with monitoring the picture on the cathode-ray tube 20. After the position of the sample has been adjusted such that the range of the sample to be photographed should be on an optical axis, the operator orders a position for a control such as focusing and the like of the electron beam. The operator inputs the order from an input unit 19, then, a bright spot P is displayed on a screen of the cathode-ray tube 20 by a control circuit 18. A position of the bright spot P is moved by the input unit 19 so as to select the range of the sample appropriate to the control such as focusing and the like of the electron beam. As a result, the electron beam is deflected by a deflection coil 11, and the electron beam is radiated to the range of the sample ordered by the bright spot.
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