Color cathode ray tube

A color cathode ray tube comprising:

• an envelope including a panel with a substantially rectangular effective portion having a substantially flat outer surface and a funnel bonded to the panel;
• a phosphor screen on the inner surface of the effective portion;
• a shadow mask having a substantially rectangular effective surface opposed to the phosphor screen and formed with a large number of electron-beam passage apertures, the effective surface being a curved surface projecting toward the phosphor screen;
• and
• an electron gun located in a neck of the funnel, for emitting electron beams toward the phosphor screen,
• the shadow mask and the panel sharing a center through which a tube axis passes and major and minor axes passing through the center and extending at right angles to the tube axis and to each other,
• the shadow mask being formed so that there are relations:
• 1>RVmin/RVmax≧0.3,
• where RVmin and RVmax are minimum and maximum values, respectively, of the minor-axis-direction curvature radius of the effective surface on the minor axis, and
• 1<RHC/RHA≦3,
• where H is the distance between the opposite ends of the effective surface in the direction of the major axis, RHA is the average major-axis-direction curvature radius of the effective surface on the major axis, defined by H/2 and a depression zH of each major-axis end of the effective surface in the direction of the tube axis, compared to the center of the effective surface, and RHC is the major-axis-direction curvature radius in the center of the effective surface.