Patent US3777203A successfully refreshed from Google Patents.
US3777203A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color picture tube shadow mask of low carbon soft steel
Assignee: Hitachi Ltd
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Filing: 1972-01-11
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Granted: 1973-12-04
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Expires: 1992-01-11
Abstract
Abstract A color picture tube in which a color selective electrode is disposed in close proximity to a phosphor screen and is provided with a plurality of openings through which electron beams emanating from electron guns pass to impinge against the phosphor dots. The color selective electrode is made of a plate of soft steel containing 0.002 to 0.012 percent by weight of carbon for minimizing the formation of undesirable projections on the side wall surface of the openings.
Inventors
- 👤 J Yamada
- 👤 E Terashima
- 👤 H Nakai
- 👤 Y Takami
- 👤 K Fukuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:25
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/06; H01J29/07; H01J2229/00; H01J2229/07; H01J2229/0727; H01J2229/0733
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
101 words
A color picture tube comprising an envelope consisting of a neck portion, a funnel portion and a panel portion, electron guns disposed within said neck portion, a phosphor screen formed on the inner surface of the front wall of said panel portion opposite to said electron guns, and a color selective electrode disposed in close proximity to said phosphor screen and having a plurality of openings for passing the electron beams emanating from said electron guns therethrough, said color selective electrode being made of a palte of soft steel containing carbon, the carbon content being 0.002 to 0.012 percent by weight.
Claim 2
Dependent Claim
101 words
A color picture tube comprising an envelope consisting of a neck portion, a funnel portion and a panel portion, electron guns disposed within said neck portion, a phosphor screen formed on the inner surface of the front wall of said panel portion opposite to said electron guns, and a color selective electrode disposed in close proximity to said phosphor screen and having a plurality of openings for passing the electron beams emanating from said electron guns therethrough, said color selective electrode being made of a palte of soft steel containing carbon, the carbon content being 0.002 to 0.012 percent by weight.
Claim 3
Dependent Claim
32 words
A color picture tube as defined in claim 1 wherein the carbon content of the soft steel from which the color selective electrode is made is 0.002 to 0.006 percent by weight.
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) | 1976-12-03 | 1977-06-04 | 1977-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-03 | 1981-06-04 | 1981-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-03 | 1985-06-04 | 1985-12-04 | $7700.00 | Window Closed / Lapsed |