| 摘要 |
PURPOSE:To reduce doming and prevent the color shift of a picture by partially forming a layer that is principally made of glass at least on the surface of an electron gun side of a shadow mask provided with a number of premeation holes on its rectangular principal surface. CONSTITUTION:A shadow mask 5 arranged in proximity and opposition to the screen 4 of a color picture tube is provided with a layer 11 made of vitrified lead silicate glass and on the surface of the electron gun 6 side while being formed symmetrically and rectangularly on both sides 1/2y including the central line h-h in the direction of the central line v-v and from 1/2w to 1/2x on both sides of the central ine v-v in the direction of the central line h-h. As a result, since the mislanding of an electron beam caused by the doming of the shadow mask 5 is increased toward the outside area from the central vicinity, the residual stress taking place when the glass and metal are sealed together can be reduced and the deterioration of color purity can be prevented by partially forming the layer 11. |
