| 摘要 |
PURPOSE:To unify the effect of the eddy current in the side wall on three electron beams by making the thickness of the side wall of a screening electrode made of nonmagnetic metal thin in the vertical direction and thick in the horizontal direction. CONSTITUTION:The thickness of the side wall of a screening electrode 1 is made thin in the vertical direction 2 and thick in the horizontal direction 3. The eddy current generated on the side wall of the screening electrode 1 by the horizontal deflection magnetic flux is made larger as the wall thickness becomes thick, and it serves as the magnetic field source affecting the beams on both sides. The wall thickness in the horizontal direction is made thick, thereby the effect of the eddy current on the in-line electron beams can be unified. As a result, the mis-convergence caused by the eddy current can be suppressed to the nonproblematic degree even if the horizontal deflection frequency is made high.
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