| 摘要 |
PURPOSE:To block the leakage radio wave by extending the inner edge of a seal ring to the proximity of a lead rod while bringing close to a lead electrode board thereby forming electrostatic capacity betweem the seal ring and the lead electrode board. CONSTITUTION:A seal ring 31 is located below a magnetic end board 10 fixed to the lower end of an anode cylinder 1. The seal ring 31 is extending toward the inside such that the inner edge will contact with the surface of an insulator 34 in wide range and brazed to the insulator 34 at the contacting face section 35. Fur thermore the inner edge is extending along the wall face of a central face 36 of the insulator 34 while a lead rod inserting hole 37 is formed at the central section. The lead rods 21, 22, 24 are passed through the insertion hole 37 and fixed to a lead electrode board 33. Since electrostatic capacity is formed between the seal ring 31 and the lead electrode board 33, the unnecessary radiation wave leaking through the surface of the lead rod and the insertion hole can be blocked reliably. |
