| 摘要 |
PURPOSE: A shadow mask and a color cathode ray tube are provided to achieve improved strength without increasing the thickness, while ensuring improved image quality level. CONSTITUTION: A shadow mask comprises a mask body(23) including a substantially rectangular effective area having a minor axis and a major axis extending at right angles to each other, and a large number of electron beam passage apertures formed in the effective area. Each of the electron beam passage apertures is formed of a communication hole connecting a larger hole opening in one surface of the effective area and a smaller hole opening in the other surface of the effective area. In a cross section of the mask body in the major axis direction, a joint portion between the larger and smaller holes of each of at least the electron beam passage apertures in the central portion of the effective area is situated in a central portion in the thickness-direction of the mask body. In a cross section of the mask body in the major axis direction, a joint portion between the larger and smaller holes of each of the electron beam passage apertures located on the major axis and in the peripheral portion of the effective area is situated closer to one of the surface sides of the effective area than the joint portion of each of the electron beam passages apertures in the central portion of the effective area. The larger hole is offset against the smaller hole in the direction of the major axis.
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