Color picture tube

A color picture tube comprising a panel in which a phosphor screen is formed on an inner surface of a substantially rectangular useful portion, and a shadow mask,

• wherein the phosphor screen is composed of a black non-light-emitting layer and a phosphor formed in a region where the black non-light-emitting layer is not formed,
• the shadow mask includes a substantially rectangular perforated region opposed to the phosphor screen, in which a number of electron beam passage apertures are arranged in vertical and horizontal directions,
• a radius of curvature of an outer surface of the useful portion of the panel is 10,000 mm or more,
• assuming that a tube axis is a Z-axis, an axis orthogonal to the Z-axis and parallel to a long side direction of the useful portion is an X-axis, an axis orthogonal to the Z-axis and parallel to a short side direction of the useful portion is a Y-axis, a distance (unit:
• mm) along the X-axis between a point where the X-axis and a peripheral edge of the useful portion cross each other and a center of the useful portion is LH, and a total number of rows of apertures composed of the electron beam passage apertures arranged on a straight line substantially parallel to the Y-axis is N, the following expression:
• 0.9≦LH/N≦1.0
• is satisfied,
• assuming that a pitch of the rows of apertures adjacent to each other is PHC at a center of the perforated region, PHH at a major axis end where the X-axis and a peripheral edge of the perforated region cross each other, and PHM at a point away from the center of the perforated region by ⅔ of a distance MH between the center of the perforated region and the major axis end along the X-axis, the following expressions:
• PHM/PHC≦1.2
• PHH/PHC≦1.4
• are satisfied, and
• the shadow mask is made of a material containing 95% or more of iron.