Shadow mask having elongated apertures concave to vertical center line and increasing in pitch along x-axis with distance from said line

摘要

The display screen of a colour cathode ray tube comprises a line pattern of elongated phosphor regions. The elongate apertures in the shadow mask having the shape of an approximately spherical sector are arranged along curved lines which during the manufacture of the tube are aligned in one flat plane with the central axis of a linear light source located in the deflection region.