| 摘要 |
The radius of curvature of an outer surface of a useful portion of a panel is 10,000 mm or more, and a shadow mask is made of a material containing 95% or more of iron. Assuming that a distance (unit: mm) along an X-axis between a center of the panel and a peripheral edge of the useful portion is LH, and a total number of rows of apertures composed of electron beam passage apertures arranged on a straight line substantially parallel to a Y-axis is N, 0.9<=LH/N<=1.0 is satisfied. Furthermore, assuming that a pitch of adjacent rows of apertures is PHC at a center of a perforated region of the shadow mask, PHH at a major axis end of the perforated region, and PHM at a point away from the center of the perforated region by 2/3 of a distance MH between the center of the perforated region and the major axis end along the X-axis, PHM/PHC<=1.2 and PHH/PHC<=1.4 are satisfied. Because of this, a color picture tube can be provided, which has satisfactory visibility, has less degradation in color purity due to doming while having a shadow mask made of an inexpensive material with satisfactory formability, and is excellent in uniformity of brightness.
|
