Patent ID: 6020678
Filing Date: 2000-02-01
Classification: H01J

Abstract:
A color cathode-ray tube comprising a panel portion, a neck portion and a funnel portion connecting said two portions and having an internal magnetic shield, said color cathode-ray tube comprising at least a fluorescent layer formed on an inner surface of a face plate of said panel portion, a shadow mask disposed opposite to said fluorescent layer, an electron gun housed in said neck portion, and the internal magnetic shield disposed in said funnel portion and made of a substantially quadrangular pyramid-shaped frame structure which has a substantially rectangular first opening of small diameter at one end adjacent to said electron gun and a substantially rectangular second opening of large diameter at the other end adjacent to said shadow mask and creased lines formed between corresponding corners of said first and second openings, wherein each of the creased lines of said internal magnetic shield is formed in such a manner that an end of an imaginary line extension of said creased line adjacent to said second opening is located on a projected plane parallel to the second opening at a point shifted by a predetermined length from the corresponding corner of said second opening in the direction of a side of the second opening, and a segment is made by connecting a predetermined point on a line connecting between said end of the imaginary line extension and the corresponding corner of the first opening to the corresponding corner of the second opening so as to form a part of the creased line adjacent to the second opening, thereby adjusting an area ratio of side faces of the internal magnetic shield.