| 摘要 |
PURPOSE:To photograph a clear picture easily further in a short time with one time shot, by observing moire fringes to adjust excitation of an objective lens to an optimum state when an electron microscope is used to photograh a grid image. CONSTITUTION:A sample 8 is firstly set to adjust magnification to, for instance, three hundred thousand times, and then a shielding plate 16 is arranged to a position crossing with an optical axis 25. As a result, a grid of an atomic arrangement image of the sample 8 interferes with a grid of an aperture image of the plate 16 to generate moire fringes in a fluorescent plate 9. These fringes are observed while controlling a power source 7 to adjust excitation of an objective lens 4, and the excitation of the lens 4 is fixed at a position, where the clearest image of the moire fringes can be seen, or in the vicinity of that position, after the plates 16 and 9 are removed from the axis 25, a grid image of the sample 8 is photographed, then the clear grid image of the sample 8 can be photographed by one time shot. |
