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AssigneeHitachi, Ltd.
InventorsMitsuru Watanabe, Katsuyoshi Tamura
Estimating the term…
A color cathode ray tube includes in combination an in-line type electron gun assembly and a dot type phosphor screen, wherein an outer panel surface is made substantially flat, an inner surface is curved and a shadow mask has round apertures or holes while having a curved shape with a convex form as projected toward the panel. The display tube is featured in that the shadow mask holes have a horizontal direction pitch Ph and vertical direction pitch Pv, that the horizontal pitch Ph has a value at terminate ends of a minor axis of the shadow mask, which value is at least 5% greater than a pitch value at the center part of the shadow mask, and that a Ph/Pv value at the shadow mask minor axis ends is greater than that at the shadow mask center. With such an arrangement, it is possible to increase the mechanical strength at a part adjacent to the shadow mask minor axis in particular.
A color cathode ray tube comprising a panel having a substantially flat outer surface and an inner surface with a convex plane projected toward the outer surface, an in-line type electron gun assembly, a dot type phosphor display screen formed on the inner panel surface, and a shadow mask disposed to oppose said inner panel surface and having a convex plane projected toward said panel, said shadow mask having an effective area with a number of at least one of substantially circular holes and substantially longitudinally lengthened holes for passing electron beams, characterized in that said number of at least one of substantially circular holes and substantially longitudinally lengthened holes have a horizontal direction pitch Ph and a vertical direction pitch Pv, that Ph has a value at a terminate end of a minor axis of the shadow mask being at least five percent (5%) greater than a value at a center part of the shadow mask, that Ph<3Pv is defined at the shadow mask center, that Ph/Pv has a value at upper and lower end portions of the shadow mask minor axis being greater than a value at the center part of the shadow mask, and that the horizontal direction pitch Ph at an end of a major axis of the shadow mask is equal to or greater than the horizontal pitch at the center part of said shadow mask.
A color cathode ray tube comprising a panel having a substantially flat outer surface and an inner surface with a convex plane projected toward the outer surface, an in-line type electron gun assembly, a dot type phosphor screen formed on the inner panel surface, and a shadow mask disposed to oppose said inner panel surface and having a convex plane projected toward said panel, said shadow mask having an effective area with a number of at least one of substantially circular holes and substantially longitudinally lengthened holes for passing electron beams, characterized in that said number of at least one of substantially circular holes and substantially longitudinally lengthened holes have a horizontal direction pitch Ph and a vertical direction pitch Pv, that Ph is substantially the same in value on a circumference with a shadow mask center being as its center, that Ph<3Pv is defined at the shadow mask center, and that Ph/Pv is greater in value at minor axis ends than at the shadow mask center.
A color cathode ray tube comprising a panel having a substantially flat outer surface and an inner surface with a convex plane projected toward the outer surface, an in-line type electron gun assembly, a dot type phosphor screen formed on the inner panel surface, and a shadow mask disposed to oppose said inner panel surface and having a convex plane projected toward said panel, said shadow mask having an effective area with a number of at least one of substantially circular holes and substantially longitudinally lengthened holes for passing electron beams, characterized in that said number of at least one of substantially circular holes and substantially longitudinally lengthened holes have a horizontal direction pitch Ph and a vertical direction pitch Pv, that a specific location exists on a line segment extending substantially parallel to a minor axis of the shadow mask at which location a horizontal direction pitch value Php of upper and lower ends are greater than a horizontal direction pitch value Phx on a major axis, while permitting establishment of a relation of Php/Phx>Wp/Wx, where Wp is a maximal horizontal length in close proximity to a long side of an effective area of the shadow mask and Wx is a diameter of the major axis, and that the horizontal direction pitch Ph at shadow mask major axis ends is equivalent to or greater than a horizontal direction pitch value at a center part of the shadow mask.
Dependencies are inferred from the claim text.