Cathode-ray tube having shadow mask for low overscan

Abstract From the Canadian patent

A cathode-ray tube includes a shadow mask having an array of apertures mounted adjacent a substantially rectangular faceplate panel with curvature along major and minor axes orthogonal to each other and to a central longitudinal axis passing through the center of the faceplate panel. The shadow mask has a border of varying width disposed between the perimeter of the apertured array and a bend line adjoining a peripheral mask skirt which substantially parallels the central axis and is supported by a shadow-mask frame oriented orthogonally to the central axis. The width of the border is narrowest at the major axis, preferably being no greater than five percent of the distance from the minor …