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US 6,204,599 B1Granted
Color cathode ray tube with graded shadow mask apertures
AssigneeKabushiki Kaisha Toshiba
InventorTatsuya Yamazaki
Life of this patent
Estimating the term…
Abstract
Electron beam passage hole arrays are arrayed on an effective surface of a shadow mask along the Y-axis direction in accordance with a predetermined quartic polynomial. The X-axis direction size of each of electron beam passage holes constituting the electron beam passage hole array is defined on the basis of the quartic polynomial such that the ratio of the hole size to the interval between electron beam passage hole arrays adjacent to each other becomes constant.
Claims8
A color picture tube comprising:
- an electron gun assembly for emitting a plurality of electron beams;
- a shadow mask having a substantially rectangular effective surface on which electron beam passage holes for passing the plurality of electron beams emitted from said electron gun assembly are formed, and a plurality of electron beam passage hole arrays each formed by arraying the plurality of electron beam passage holes along a minor axis direction parallel to a short side of said effective surface are arranged in parallel along a major axis direction parallel to a long side of said effective surface;
- and
- a phosphor screen for emitting light upon landing the electron beams which have passed through the electron beam passage holes of said shadow mask,
- wherein on an orthogonal coordinate system using a center of said effective surface of said shadow mask as an origin and a major axis passing through the origin and a minor axis passing through the origin as coordinate axes,
- a major-axis-direction size of each of the electron beam passage holes formed in said shadow mask is defined on the basis of a function such that the size changes depending on said effective surface, and on the minor axis, the hole size decreases and then increases from the origin toward said long side of said effective surface, increases and then decreases from a point on the major axis, which is separated from the origin by 1/3 a length of said major axis, toward said long side along the minor axis direction, and, on said short side of said effective surface, decreases and then increases from an end of the major axis toward a corner of said effective surface.
3 more elements
A color picture tube comprising:
- an electron gun assembly for emitting a plurality of electron beams;
- a shadow mask having a substantially rectangular effective surface on which electron beam passage holes for passing the plurality of electron beams emitted from said electron gun assembly are formed, and a plurality of electron beam passage hole arrays each formed by arraying the plurality of electron beam passage holes along a minor axis direction parallel to a short side of said effective surface are arranged in parallel along a major axis direction parallel to a long side of said effective surface;
- and
- a phosphor screen for emitting light upon landing the electron beams which have passed through the electron beam passage holes of said shadow mask,
- wherein on an orthogonal coordinate system using a center of said effective surface of said shadow mask as an origin and a major axis passing through the origin and a minor axis passing through the origin as coordinate axis,
- a major-axis-direction size of each of the electron beam passage holes formed in said shadow mask is defined on the basis of a function such that the size changes depending on said effective surface, and on the minor axis, the hole size is substantially constant from the origin to an intermediate portion between the major axis and said long side toward said long side of said effective surface and decreases from the intermediate portion toward said long side along the minor axis direction, is substantially constant from a point on the major axis, which is separated from the origin by 1/3 a length of said major axis and said long side and increases from the intermediate portion toward said long side along the minor axis direction, and on said short side of said effective surface, increases from an end of the major axis toward a corner of said effective surface.
3 more elements
Dependencies are inferred from the claim text.