| 摘要 |
PURPOSE:To effectively suppress the doming of a shadow mask and prevent color purity deterioration such as color drift and irregularity by making the center section and peripheral section of the main face effective section of the shadow mask of an electron absorbing layer different in thickness. CONSTITUTION:An electron absorbing layer is formed on the electron gun 6 side of the main face effective section of shadow masks 7, and the center section and peripheral section of the main face effective section of this electron absorbing layer are made different in thickness. That is, the film thickness of the electron absorbing layer is gradually decreased from the center of a screen to the periphery, and this equipotential distribution 27 is formed slantly to a shadow mask 25. An electron beam 26 is strongly deflected in the direction apart from a tube axis 21 by this equipotential distribution 27, i.e., decelerating electric field. Therefore, the landing position 26a of the electron beam expected to be moved toward the tube axis 21 from the preset landing position 23a by a doming phenomenon is offset to be returned to the original landing position 23a again. Accordingly, the mislanding of the electron beam can be suppressed and reduced even if a doming phenomenon occurs.
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