US3571652A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Degaussing device for color picture tube having parallel-slitted beam-selecting grid
Assignee: Sony Corp
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Filing: 1969-04-14
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Granted: 1971-03-23
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Expires: 1989-04-14
Abstract
Abstract A degaussing structure for a video tube which serves to demagnetize the tube and an apertured beam-selecting member in the tube. A shroud surrounds the forward portion of the tube and the apertured beam-selecting member. A pair of degaussing coils which are connected in series are wrapped around cutout areas in the shroud at the top and bottom thereof such that the magnetic flux produced by the current carrying coils is in a direction to degauss the apertured beam-selecting member.
Inventors
- 👤 Kenjiro Shiobara
- 👤 Yuzo Fuse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:59
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/003; H01J2229/00; H01J2229/0007; H01J2229/0046; H01J2229/0053
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
149 words
The combination of a color video picture tube comprising a tube envelope having a face plate at one end with a phosphor screen thereon, an apertured beam-selecting means mounted within said envelope adjacent said screen and having the apertures thereof in the form of parallel, elongated slits, a shroud of substantially high permeance partially covering the tube envelope and having a portion thereof adjacent said beam-selecting means, degaussing coils carried by said shroud at opposed locations on the latter such that a degaussing current passed through said coils produces a magnetic flux which passes through said tube envelope and through said beam-selecting means in the direction of said parallel slits prior to return to said coils by way of said shroud, and circuit means for supplying said degaussing current to said coils in the form of a progressively decreasing AC current during warmup of the color video picture tube.
Claim 2
Dependent Claim
149 words
The combination of a color video picture tube comprising a tube envelope having a face plate at one end with a phosphor screen thereon, an apertured beam-selecting means mounted within said envelope adjacent said screen and having the apertures thereof in the form of parallel, elongated slits, a shroud of substantially high permeance partially covering the tube envelope and having a portion thereof adjacent said beam-selecting means, degaussing coils carried by said shroud at opposed locations on the latter such that a degaussing current passed through said coils produces a magnetic flux which passes through said tube envelope and through said beam-selecting means in the direction of said parallel slits prior to return to said coils by way of said shroud, and circuit means for supplying said degaussing current to said coils in the form of a progressively decreasing AC current during warmup of the color video picture tube.
Claim 3
Dependent Claim
76 words
The combination according to claim 1, in which said slits extend vertically, said portion of the shroud adjacent the beam-selecting means is an edge portion thereof and an adjacent raised portion, said shroud has cutouts extending from said edge portion into the adjacent raised portion at opposite sides of the top and bottom of the shroud, and said coils are wrapped about the top and bottom sections of said raised portion between the respective cutouts therein.
Claim 4
Dependent Claim
58 words
The combination according to claim 2, in which said edge portion is constituted by a radial flange, and a ring of high permeance extends around the tube envelope in the region of the face plate and has a radial flange abutting said flange constituting said edge portion to provide with the latter a path for the magnetic flux.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-22 | 1974-09-21 | 1975-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-22 | 1978-09-21 | 1979-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-22 | 1982-09-21 | 1983-03-23 | $7700.00 | Window Closed / Lapsed |