US 4,142,131 AGranted

Color picture tube

AssigneeHitachi, Ltd.

InventorsKunio Ando, Ryoichi Hirota, Kuniharu Osakabe, Koichi Maruyama

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Abstract

A color picture tube of an in-line type comprises means for deflecting beams of electron emitted from electron guns of the in-line type aligned horizontally such that for the horizontal deflection, the central beam is subjected to a greater deflection than side beams and for the vertical deflection, the side beams are subjected to a greater deflection than the central beam. Two vertical magnetic pole piece plates which are long vertically and thin horizontally are so disposed as to sandwich the central beam near the outlet of the central electron gun in order to weaken horizontal deflection magnetic field acting on the central beam, whereby a portion of the horizontal deflection magnetic flux acting on the central beam is absorbed by the two magnetic pole piece plates. The vertical deflection magnetic field is almost not affected by these vertical magnetic pole piece plates. Further, two horizontal magnetic pole piece plates which are long horizontally and short vertically are so disposed as to sandwich side beams near the outlets of the side electron guns in order to weaken vertical deflection magnetic fields acting on the side beams and to intensity vertical deflection magnetic fields acting on the central beam.

Claims15

Dependent claims

A color picture tube device comprising:

a color picture tube having a target and three electron guns aligned in line so as to provide a pair of side electron guns and a center electron gun producing three electron beams directed to said target;
deflecting means coupled to said color picture tube for simultaneously generating a first deflection magnetic field for deflecting beams of electrons emitted from said electron guns in a first direction and a second deflection magnetic field for deflecting said beams of electrons in a second direction substantially perpendicular to said first direction so as to scan said target, said deflecting means producing such a first distribution of deflection magnetic field in the first direction that the side beams emitted from the side electron guns are deflected more greatly than the central beam emitted from the center electron gun and a second distribution of deflection magnetic field in the second direction such that the central beam is deflected more greatly than the side beams;
first magnetic field modifying means disposed in a space downstream of the electron guns in which the deflection magnetic fields prevail for causing the deflection magnetic field in the first direction acting on the side beams to be relatively weakened in relation to that acting on the central beam;
and
second magnetic field modifying means disposed in said space for causing the deflection magnetic field in the second direction acting on the central beam to be weakened in relation to that acting on the side beams.

2 more elements

Dependencies are inferred from the claim text.