Sony Corporation

Nippon Steel Corporation

Jfe Steel Corporation

Keisuke Fukumizu

Hiroaki Kato

Teruo Takeuchi

Yasuo Sato

Takeshi Harada

Hideki Matsuoka

Reiko Sugihara

Kenji Tahara

Ryoichi Yoshihara

Takahide Shimazu

Tatsuo Amaike

Noriko Kubo

A steel sheet for an inner magnetic shield has a ratio of the anhysteretic magnetic permeability in the rolling direction to the anhysteretic magnetic permeability in the transversal direction, which is not higher than 0.7 or not lower than 1.4, preferably not higher than 0.5 or not lower than 2.0. A higher value of the two anhysteretic magnetic permeability values in the rolling direction and in the transversal direction is not lower than 18000. The inner magnetic shield formed of the particular steel sheet has a substantially truncated pyramid body which has a pair of short side members of a screen and a pair of long side members of a screen. The short side members are joined to the long side members at edge portions of the truncated pyramidal inner magnetic shield. The direction, in which the anhysteretic magnetic permeability of the steel sheet is the higher value, corresponds to the horizontal plane direction of the short side member. In addition, the direction, in which the anhysteretic magnetic permeability of the steel sheet is the higher value, corresponds to as required to the horizontal plane direction of the long side member.

Steel sheet for inner magnetic shield and method of producing the same, inner magnetic shield, and color cathode ray tube

A 0.1 to 0.5 mm-thick plated steel sheet having high coercive force and magnetic flux density is provided by hot rolling a slab comprising by weight carbon: 0.01 to 0.09%, silicon: not more than 1.0%, phosphorus: not more than 0.3%, manganese: not more than 1.5%, sulfur: not more than 0.04%, aluminum: not more than 1.0%, and nitrogen: not more than 0.01% with the balance consisting of iron and unavoidable impurities, cold rolling the hot rolled sheet, annealing the cold rolled sheet to prepare a steel sheet having an average grain diameter of 3 to 15 .mu.m, temper rolling the steel sheet with a reduction ratio of not more than 3%, and plating the temper rolled sheet with chromium or nickel. This enables the provision of a magnetic shielding material having no significant drift and very good electron beam landing properties.

Magnetic shielding material for television cathode-ray tube and process

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Tokyo, Japan

Keisuke Fukumizu