Color display tube comprising an internal magnetic shield

摘要

A color display tube with an elongated phosphor screen having a pattern of discrete phosphor elements. In order to reduce landing errors of the electron beams, in particular in the X direction, and simultaneously minimize the amount of magnetic material used for the internal magnetic shield, the color display tube has an internal magnetic shield consisting of a tub that is deep-drawn from a foil, which tube has a bottom with an aperture for allowing passage of electrons. Material of the bottom adjoining the aperture for allowing passage of electrons has been bent outwards from the plane of the bottom. In this manner, material of the bottom of the tub which would otherwise have been cut away is used to enlarge the "virtual" height of the magnetic shield.