CRT colour selection electrode - has holes in mask shaped so that secondary electrons reflected from mask rim are prevented from passing through

摘要

The colour selection mask is bent like the picture screen. Its region surrounding that provided with holes for the electron beams is bent parallel to the tube axis. Surfaces forming the sides of the holes (11) in the colour selection mask (3) are shaped, at least in the mask regions near the edges, so that electrons (8) released and/or reflected by the primary electron beams at the mask edge (4) cannot pass through the holes (11), but fall on the surfaces of the holes towards the tube's axis.