| 摘要 |
PROBLEM TO BE SOLVED: To realize an electron beam device provided with a field emission type electron gun, which can be used under optimum conditions within any region of irradiation current. SOLUTION: An electron beam, emitted from an electron emitter 1, is formed into a parallel beam or a full-line mode beam by a first condenser lens 4. Consequently, the electron beam, restricted by an anode electrode 3, can be suppressed to minimum. Since the excitation for the first condenser lens 4 is fixed to parallel beam conditions, the movement of a virtual light source will not occur, and the accuracy of an optical axis is improved.
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