Color cathode ray tube with curved shadow mask having central recessed portions

Abstract

A shadow mask of a color cathode-ray tube has a substantially rectangular mask main body and a substantially rectangular mask frame fixed to a skirt portion of the mask main body. The mask main body has a curved effective surface formed with a large number of electron-beam passage apertures and opposing the phosphor screen, a non-aperture portion surrounding the outer periphery of this effective surface, and a skirt portion formed in a bent on the outer periphery of the non-aperture portion. The mask main body has a long axis extending in a horizontal direction and crossing with a tube axis, and a short axis extending in a vertical direction and crossing with both the tube axis and the long axis. The effective surface and the non-aperture portion of the mask main body are formed in a curved surface having a radius of curvature in the short axis direction. At each long side of the mask main body, each end portion of the short axis of the effective surface and the non-aperture portion is recessed from any other adjacent part, in a direction leaving from the phosphor screen along the tube axis. The radius of curvature in a short axis direction near the short axis of the effective surface and the non-aperture portion of the mask main body is smaller than the radius of curvature in the short axis direction at other parts.