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US 4,229,675 AGranted
Color picture tube with internal funnel shaped magnetic shield
AssigneeHitachi, Ltd.
InventorsTakeshi Matsuki, Koichi Maruyama, Kuniharu Osakabe, Sakae Kunitoh
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Abstract
An in-line stripe type color picture tube comprises an inner magnetic shield member having sufficient shield effect against both individual vertical and horizontal components of the earth magnetism and composite components as well. The inner magnetic shield member prevents unwanted shifts of electron beams to ensure that the positional relationship between a fluorescent screen and landing electron beams may have sufficient tolerances and color blur on the fluorescent screen may be prevented.
Claims10
An in-line stripe type color picture tube comprising:
- a bulb including a neck portion, a funnel portion and a panel portion for hermetically sealing a large diameter opening of the funnel portion,
- an electron gun assembly disposed in the neck portion of the bulb,
- a fluorescent screen formed on the inner surface of the panel portion,
- a shadow mask disposed in the bulb and opposing the fluorescent screen with a predetermined spacing,
- a magnetic shield member in the form of a funnel opposing the shadow mask and extending along the curvature of the funnel portion for surrounding a travel region of electron beams emitted from the electron gun assembly, said magnetic shield member having a transverse cross-sectionally central portion defining an area of a predetermined, substantially constant width and a higher reluctance than that of the magnetic shield member, said higher reluctance area perpendicularly intersecting a scanning direction of the electron beams.
2 more elements
Dependencies are inferred from the claim text.