| 摘要 |
PURPOSE:To prevent influence of excessive electrons while to improve the positioning accuracy by bringing a shielding electrode of particular shape into contact with the tubular section of second grid in an electron gun for image pickup tube thereby shielding the gaps at the opposite sides of beam disc. CONSTITUTION:A shielding electrode 30 is formed with a circular plane of same diameter with the inner diameter at the tubular section of second grid 4 while providing an elongated recess which is line symmetrical against the diameter while having the inside width larger than the outer diameter at the tubular section of beam disc 2 and a round hole 30a in the bottom face in the central section. Then it is fixed to second grid 4 to shield the gaps occurring at the opposite sides of beam disc 2 thereafter fixed with the beam disc 2 and further assembled with first and third grids 1, 6 thus to form an electron gun for image pickup tube. Consequently, deterioration of regulation of high voltage power source due to excessive electrons can be prevented while aligning accuracy of beam limiting hole 2a can be improved easily.
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