Patent ID: 6218772
Filing Date: 2001-04-17
Classification: H01J

Abstract:
A color cathode-ray tube comprising:an envelope including a panel having a substantially rectangular effective portion;a phosphor screen formed on an inner surface of the effective portion; anda shadow mask arranged in the envelope and opposing the phosphor screen;the shadow mask including:a mask main body having a substantially rectangular main surface portion formed of a curved face having a large number of electron beam passage apertures, the main surface portion having a center through which a tube axis passes, a longer axis and a shorter axis passing through the center and perpendicular to each other, and a skirt portion raised in peripheral edges of the main surface portion; anda substantially rectangular mask frame being joined to an outer periphery of the skirt portion of the mask main body,the skirt portion of the mask main body having a pair of longer side walls extending substantially in parallel to the longer axis, and a pair of shorter side walls extending substantially in parallel to the shorter axis; andeach of the longer side walls including a pressing portion located at a region through which the shorter axis passes the pressing portion protruding toward the mask frame and pressing the mask frame so as to generate residual internal stress in the main surface portion.