Patent ID: 6326722
Filing Date: 2001-12-04
Classification: H01J

Abstract:
A color cathode-ray tube comprising:a vacuum envelope having a panel with a substantially rectangular effective portion;a phosphor screen formed on an inner surface of the effective portion; anda substantially rectangular shadow mask arranged to face the phosphor screen,wherein the shadow mask has a mask body and a substantially rectangular mask frame attached to a peripheral portion of the mask body, the mask body having a substantially rectangular curved effective surface opposed to the phosphor screen, and a number of electron beam passage apertures being formed in the effective surface,the shadow mask and the panel both have a center through which a tube axis extends, and a long axis and a short axis extending through the center at right angles with each other, andthe effective surface of the mask body has a curvature in a direction of the long axis, which is set within a range of about 0 to 3.times.10.sup.-4 (1/mm) over an area from a center of the effective surface to a middle portion of the effective surface in the direction of the long axis, a curvature at a peripheral portion in the direction of the long axis is set to be greater than that at the middle portion, and a curvature on the short axis in the direction of the short axis successively increases over a distance equal to at least two thirds of a distance between the center and an effective end of the short axis.