| 摘要 |
PROBLEM TO BE SOLVED: To provide an electron gun having an electrode having minimal beam hole. SOLUTION: A necessary electrode G2 as a component of the electron gun is composed of a plurality of electrode plates G2A, G2B, and a beam hole 19 of at least one electrode plate of the electrode G2 has a small diameterϕd which is smaller than the criteria of stable machining at an integral pseudo plate thickness T1, based on a plurality of the electrode plates G2A, G2B.
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