US4306172A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shadow mask of braun tube for color TV and process for manufacturing the same
Assignee: Dai Nippon Printing Co Ltd
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Filing: 1979-11-09
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Granted: 1981-12-15
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Expires: 1999-11-09
Abstract
Abstract A shadow mask of a Braun tube for a color TV made of a steel alloy having the following compositions in weight percent: C≦0.12, 0.2≦Mn≦1.5, 0.3≦Si≦1.5, 1.0≦2Si+Mn, 0.005≦Al≦0.030, and the balance being Fe and unavoidable impurities. A cold rolled and annealed strip made from such a steel alloy has a Vickers hardness of at least 110 so that it can be easily and satisfactorily processed in the subsequent hole-formation step.
Inventors
- 👤 Takashi Matsukura
- 👤 Norio Tsukiji
- 👤 Yoshiaki Ishimoto
- 👤 Masahiro Shimose
- 👤 Yasuo Imamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:40
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/14; H01J9/142; H01J29/00; H01J29/02; H01J29/06; H01J29/07; H01J2229/00; H01J2229/07; H01J2229/0727; H01J2229/0733; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/496; Y10T29/49995
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
59 words
A shadow mask of a Braun tube for a color TV made of a strip of low carbon steel, characterized in that said low carbon steel falls within the following composition limits in weight percent: C≦0.12, 0.2<Mn<1.5, 0.3≦Si≦1.5, 1.0≦2Si+Mn, 0.005≦Al≦0.030, and the balance being Fe and impurities unavoidably coming into said steel during the course of the production thereof.
Claim 2
Dependent Claim
59 words
A shadow mask of a Braun tube for a color TV made of a strip of low carbon steel, characterized in that said low carbon steel falls within the following composition limits in weight percent: C≦0.12, 0.2<Mn<1.5, 0.3≦Si≦1.5, 1.0≦2Si+Mn, 0.005≦Al≦0.030, and the balance being Fe and impurities unavoidably coming into said steel during the course of the production thereof.
Claim 3
Dependent Claim
25 words
A shadow mask in accordance with claim 1 having a thickness of not more than 0.2 mm and a Vickers hardness of at least 110.
Claim 4
Dependent Claim
16 words
A shadow mask in accordance with claim 2 having a Vickers hardness of at least 120.
Claim 5
Dependent Claim
137 words
A process for manufacturing a shadow mask of a Braun tube for a color TV comprising the steps of subjecting a strip of low carbon steel to a cold rolling finish to provide a steel strip material of not more than 0.2 mm in thickness, annealing the so-rolled material, forming predetermined patterns of holes in the annealed strip material by a photoetching technique, cutting the material into individual flat masks of a predetermined dimension, and pressforming the flat mask into a desired shape, characterized in that said low carbon steel falls within the following composition limits in weight percent: C≦0.12, 0.2≦Mn≦1.5, 0.3≦Si≦1.5, 1.0≦2Si+Mn, 0.005≦Al≦0.030, and the balance being Fe and impurities unavoidably coming into said steel during the course of the production thereof, and that said annealed strip material has a Vickers hardness of at least 110.
Claim 6
Dependent Claim
137 words
A process for manufacturing a shadow mask of a Braun tube for a color TV comprising the steps of subjecting a strip of low carbon steel to a cold rolling finish to provide a steel strip material of not more than 0.2 mm in thickness, annealing the so-rolled material, forming predetermined patterns of holes in the annealed strip material by a photoetching technique, cutting the material into individual flat masks of a predetermined dimension, and pressforming the flat mask into a desired shape, characterized in that said low carbon steel falls within the following composition limits in weight percent: C≦0.12, 0.2≦Mn≦1.5, 0.3≦Si≦1.5, 1.0≦2Si+Mn, 0.005≦Al≦0.030, and the balance being Fe and impurities unavoidably coming into said steel during the course of the production thereof, and that said annealed strip material has a Vickers hardness of at least 110.
Claim 7
Dependent Claim
20 words
A process in accordance with claim 4 wherein said annealed strip material has a Vickers hardness of at least 120.
Claim 8
Dependent Claim
47 words
A process in accordance with claim 4 or 5, wherein said strip of low carbon steel is subjected to a cold rolling finish with a rolling reduction of 20 to 80% and the so-rolled strip material is annealed at a temperature of 520° C. to 650° C.
Claim 9
Dependent Claim
52 words
A process in accordance with claim 6 wherein said strip of low carbon steel is subjected to a cold rolling finish with a rolling reduction of at least 30% and the so-rolled strip material is annealed in the form of a tight coil at a temperature of not more than 620° C.
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) | 1984-12-14 | 1985-06-15 | 1985-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-14 | 1989-06-15 | 1989-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-14 | 1993-06-15 | 1993-12-15 | $7700.00 | Window Closed / Lapsed |