US4558252A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color cathode ray tube with frame, mask or shield having an oxidized layer
Assignee: Toshiba Corp
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Filing: 1982-11-03
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Granted: 1985-12-10
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Expires: 2002-11-03
Abstract
Abstract A color cathode ray tube having a mask frame, a shadow mask attached to the mask frame and inner shield attached to the mask frame. At least one of these parts is made substantially of iron (Fe) and has a oxidized layer on its surface. That part further includes silicon (Si), aluminum (Al) and chromium (Cr) as impurity elements in weight amounts satisfying the following relation: Cr≧1/3(Al+Si).
Inventors
- 👤 Masaharu Kanto
- 👤 Hisato Kihara
- 👤 Koichi Teshima
- 👤 Michihiko Inaba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:34
CPC Classifications
C; C07; C07D; C07D275/00; C07D275/04; C07D275/06; H; H01; H01J; H01J29/00; H01J29/02; H01J29/06; H01J29/07; H01J2229/00; H01J2229/07; H01J2229/0727; H01J2229/0733; H01J2229/0777; H01J2229/0783
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
152 words
A color cathode ray tube comprising: an envelope having a face plate, a funnel portion joined to said face plate and a neck portion joined to said funnel portion; an electron gun disposed within said neck portion; a phosphor screen formed on said inner surface of said face plate; a mask frame mounted to said face plate; a shadow mask attached to said mask frame, said shadow mask having a plurality of apertures therein and which faces said phosphor screen; and an inner shield attached to said mask frame; wherein at least one part of said mask frame, said shadow mask and said inner shield is made substantially of iron and has an oxidized layer on a surface thereof, said iron part further including silicon, aluminum and chromium as impurity elements in weight amounts satisfying the following relation: Cr≧1/3(Al+Si) wherein Cr+Al+Si≦0.44 percent by weight, to enhance the adhesion of the oxidized layer.
Claim 2
Dependent Claim
152 words
A color cathode ray tube comprising: an envelope having a face plate, a funnel portion joined to said face plate and a neck portion joined to said funnel portion; an electron gun disposed within said neck portion; a phosphor screen formed on said inner surface of said face plate; a mask frame mounted to said face plate; a shadow mask attached to said mask frame, said shadow mask having a plurality of apertures therein and which faces said phosphor screen; and an inner shield attached to said mask frame; wherein at least one part of said mask frame, said shadow mask and said inner shield is made substantially of iron and has an oxidized layer on a surface thereof, said iron part further including silicon, aluminum and chromium as impurity elements in weight amounts satisfying the following relation: Cr≧1/3(Al+Si) wherein Cr+Al+Si≦0.44 percent by weight, to enhance the adhesion of the oxidized layer.
Claim 3
Dependent Claim
23 words
A color cathode ray tube according to claim 1, wherein the weight amounts of silicon, aluminum and chromium satisfy the following relation: Cr≧(Al+Si).
Claim 4
Dependent Claim
17 words
A color cathode ray tube according to claim 1, wherein said iron part is said shadow mask.
References Cited (Backward Citations)
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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) | 1988-12-09 | 1989-06-10 | 1989-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-09 | 1993-06-10 | 1993-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-09 | 1997-06-10 | 1997-12-10 | $7700.00 | Window Closed / Lapsed |