US4581560A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron gun for color picture tube
Assignee: Hitachi Ltd
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Filing: 1982-12-10
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Granted: 1986-04-08
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Expires: 2002-12-10
Abstract
Abstract An electron gun used in a color picture tube having means for emitting three electron beams toward the fluorescent screen, and main lenses for focusing the electron beams on the fluorescent screen. The main lenses are constituted by two envelopes spaced out from each other and adapted to surround the electron beams, and two electrode plates located on the confronting end surfaces of the envelopes and provided with three apertures aligning on a line for conducting the three electron beams. At least one of the two electrode plates is recessed relative to another electrode plate and disposed inside the envelope, and the recessed electrode plate is structured such that non-rotational symmetry of the lens caused by the recess of the electrode is corrected.
Inventors
- 👤 Shoji Shirai
- 👤 Masaaki Yamauchi
- 👤 Kazuo Majima
- 👤 Hiroshi Takano
- 👤 Masakazu Fukushima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:04
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/46; H01J29/48; H01J29/50; H01J29/503
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
137 words
An electron gun for a color picture tube having means for emitting three electron beams toward a fluorescent screen, and lenses for focusing said electron beams on said fluorescent screen, characterized in that said lenses are constituted by two electrodes spaced out from each other and adapted to surround said electron beams, each electrode including an electrode plate having three apertures aligned on a line for conducting said electron beams, at least one of said electrode plates being recessed relative to another electrode plate and disposed inside said electrode, said apertures formed in said recessed electrode plate having a smaller dimension in the direction of said alignment of apertures than the dimension in the direction perpendicular to said alignment direction so that non-rotational symmetry of said lenses caused by the recess of said electrode plate is corrected.
Claim 2
Dependent Claim
137 words
An electron gun for a color picture tube having means for emitting three electron beams toward a fluorescent screen, and lenses for focusing said electron beams on said fluorescent screen, characterized in that said lenses are constituted by two electrodes spaced out from each other and adapted to surround said electron beams, each electrode including an electrode plate having three apertures aligned on a line for conducting said electron beams, at least one of said electrode plates being recessed relative to another electrode plate and disposed inside said electrode, said apertures formed in said recessed electrode plate having a smaller dimension in the direction of said alignment of apertures than the dimension in the direction perpendicular to said alignment direction so that non-rotational symmetry of said lenses caused by the recess of said electrode plate is corrected.
Claim 3
Dependent Claim
20 words
An electron gun according to claim 1, wherein said apertures formed in said recessed electrode plate have an elliptical shape.
Claim 4
Dependent Claim
36 words
An electron gun according to claim 1, wherein said apertures formed in said recessed electrode plate are shaped such that end points of two arcs are connected by two parallel lines perpendicular to said alignment direction.
Claim 5
Dependent Claim
63 words
An electron gun according to claim 1, wherein the central aperture out of said apertures formed in said recessed electrode plate has a symmetric axis perpendicular to said alignment direction, while outer apertures do not have symmetric axes parallel to said first-mentioned symmetric axis, said outer apertures being formed so that they are symmetric with each other with respect to respective symmetric axes.
Claim 6
Dependent Claim
40 words
An electron gun according to claim 1, wherein said two electrodes have confronting end surfaces, at least said recessed electrode plate of one of said electrodes being disposed to oppose said electrode plate of the other of said two electrodes.
Claim 7
Dependent Claim
68 words
An electron gun according to claim 5, wherein the central aperture of said aligned apertures formed in said opposing electrode plates has a symmetric axis perpendicular to said alignment direction, while outer apertures of said opposing electrode plates do not have symmetric axes parallel to said first-mentioned symmetric axis, said outer apertures being formed so that they are symmetric with each other with respect to respective symmetric axes.
Claim 8
Dependent Claim
20 words
An electron gun according to claim 5, wherein said apertures formed in said recessed electrode plate have an elliptical shape.
Claim 9
Dependent Claim
36 words
An electron gun according to claim 5, wherein said apertures formed in said recessed electrode plate are shaped such that end points of two arcs are connected by two parallel lines perpendicular to said alignment direction.
Claim 10
Dependent Claim
193 words
An electron gun for a color picture tube having means for emitting three electron beams toward a fluorescent screen, and lenses for focusing said electron beams on said fluorescent screen, characterized in that said lenses are constituted by two electrodes spaced out from each other and adapted to surround said electron beams, each electrode including an electrode plate having three apertures aligned on a line for conducting said electron beams, at least one of said electrode plates being recessed relative to another electrode plate and disposed inside said electrode, means for correcting non-rotational symmetry of said lenses caused by the recess of electrode plate, said correcting means including a cylinder located coaxially with respect to each aperture, said cylinder having a height varying along the circumferential direction, said two electrodes having confronting end surfaces, at least said recessed electrode plate of one of said electrodes being disposed to oppose said electrode plate of the other of said two electrodes, each of said electrodes having a recessed electrode plate recessed with respect to the confronting end surface of the associated electrode, and said cylinders of said opposing recessed electrode plates extending toward one another.
Claim 11
Dependent Claim
193 words
An electron gun for a color picture tube having means for emitting three electron beams toward a fluorescent screen, and lenses for focusing said electron beams on said fluorescent screen, characterized in that said lenses are constituted by two electrodes spaced out from each other and adapted to surround said electron beams, each electrode including an electrode plate having three apertures aligned on a line for conducting said electron beams, at least one of said electrode plates being recessed relative to another electrode plate and disposed inside said electrode, means for correcting non-rotational symmetry of said lenses caused by the recess of electrode plate, said correcting means including a cylinder located coaxially with respect to each aperture, said cylinder having a height varying along the circumferential direction, said two electrodes having confronting end surfaces, at least said recessed electrode plate of one of said electrodes being disposed to oppose said electrode plate of the other of said two electrodes, each of said electrodes having a recessed electrode plate recessed with respect to the confronting end surface of the associated electrode, and said cylinders of said opposing recessed electrode plates extending toward one another.
Claim 12
Dependent Claim
142 words
An electron gun for a color picture tube having means for emitting three electron beams toward a fluorescent screen, and lenses for focusing said electron beams on said fluorescent screen, characterized in that said lenses are constituted by two electrodes spaced out from each other and adapted to surround said electron beams, each electrode including an electrode plate having three apertures aligned on a line for conducting said electron beams, at least one of said electrode plates being recessed relative to another electrode plate and disposed inside said electrode, means for correcting non-rotational symmetry of said lenses caused by the recess of said electrode plate, said correcting means including configurating said recessed plate as a curved surface plate with the distance from the recess of each aperture to an end surface of the associated electrode varying along the circumference of said aperture.
Claim 13
Dependent Claim
142 words
An electron gun for a color picture tube having means for emitting three electron beams toward a fluorescent screen, and lenses for focusing said electron beams on said fluorescent screen, characterized in that said lenses are constituted by two electrodes spaced out from each other and adapted to surround said electron beams, each electrode including an electrode plate having three apertures aligned on a line for conducting said electron beams, at least one of said electrode plates being recessed relative to another electrode plate and disposed inside said electrode, means for correcting non-rotational symmetry of said lenses caused by the recess of said electrode plate, said correcting means including configurating said recessed plate as a curved surface plate with the distance from the recess of each aperture to an end surface of the associated electrode varying along the circumference of said aperture.
Claim 14
Dependent Claim
35 words
An electron gun according to claim 10, wherein said recessed electrode plate is formed of a curved surface plate having a curved surface which is common to said apertures formed in said recessed electrode plate.
Claim 15
Dependent Claim
33 words
An electron gun according to claim 10, wherein said recessed electrode plate is formed of a curved surface plate having curved surfaces which correspond to said apertures formed in said recessed electrode plate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-04-07 | 1989-10-07 | 1990-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-07 | 1993-10-07 | 1994-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-07 | 1997-10-07 | 1998-04-08 | $7700.00 | Window Closed / Lapsed |