| 摘要 |
PROBLEM TO BE SOLVED: To provide an electron gun structure capable of increasing correction sensitivity of a quadrupole lens and shortening a total length of the electron gun structure. SOLUTION: This electron gun structure comprises a negative electrode, a control electrode 2, an accelerating electrode 3, focusing electrodes 6(1), 6(2), and a positive electrode 7. Electron beam passing holes are provided to these electrodes 2, 3, 6(1), 6(2), and 7, and these electrodes 2, 3, 6(1), 6(2), and 7 are supported and fixed with a predetermined interval by an insulating holding body 12. The control electrode 2, the accelerating electrode 3, the focusing electrodes 6(1), 6(2), and the positive electrode 7 are assembled by using a beading jig. Then, a plate-shaped electrode 9 provided with electrode beam passing holes 9C, 9L, 9R is welded to at least the electrode 6(1) out of a plurality of the electrodes comprising the focusing electrodes 6(1), 6(2). The electron beam passing holes 9C, 9L, 9R of the plate-shaped electrode 9 having a smaller diameter than that of the electron beam passing holes 5C, 5L of an electrode 5 on a negative electrode side of the electrode 6(1) having the welded plate shaped electrode 9.
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