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Patent US4052641A successfully refreshed from Google Patents.
US4052641A
Expired / Lapsed
US
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Electrically conductive coating in cathode ray tube
Assignee: Corning Glass Works
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Filing: 1976-05-24
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Granted: 1977-10-04
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Expires: 1996-05-24
Abstract
Abstract An improved conductive coating for the inner wall of a cathode ray tube is disclosed. The coating consists essentially of 5-25% of at least one of the alkali metal oxides Na 2 O, K 2 O and Li 2 O, 20-80% SiO 2 , 2-25% of at least one oxide selected from the group consisting of Ag 2 O, CuO, CdO, CaO, SrO, BaO, CoO, PbO, MgO, HgO, NiO, ZnO, and MnO, 10-50% carbon, and 0-50% of a filler pigment, the total content of silica plus pigment being 45-85%.
Inventors
- 👤 Ellen K. Dominick
- 👤 Dale R. Wexell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:59
CPC Classifications
H; H01; H01B; H01B1/00; H01B1/14; H01B1/18; H01J; H01J29/00; H01J29/86; H01J29/88; H01J2229/00; H01J2229/88; H01J2229/882
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
152 words
In a cathode ray tube comprising a glass faceplate upon which a viewing screen is mounted, a glass neck portion within which an electron gun is mounted, and a glass funnel portion having an electrically conductive coating on at least a portion of its inner wall, the improvement comprising a coating mixture fired at 350°-525° C. to a hard, smooth, glassy, electrically conductive coating exhibiting good durability and resistance to weathering, said coating consisting essentially, in weight percent of total solids, of 5-25% total of at least one of the alkali metal oxides Na 2 O, K 2 O, and Li 2 O, 20-80% SiO 2 , 2- 25% of at least one oxide selected from the group consisting of Ag 2 O, CuO, CdO, CaO, SrO, BaO, CoO, PbO, MgO, HgO, NiO, ZnO, and MnO, 10-50% carbon, and 0-50% of a filler pigment, the total of silica and pigment being 45-85%.
Claim 2
Dependent Claim
152 words
In a cathode ray tube comprising a glass faceplate upon which a viewing screen is mounted, a glass neck portion within which an electron gun is mounted, and a glass funnel portion having an electrically conductive coating on at least a portion of its inner wall, the improvement comprising a coating mixture fired at 350°-525° C. to a hard, smooth, glassy, electrically conductive coating exhibiting good durability and resistance to weathering, said coating consisting essentially, in weight percent of total solids, of 5-25% total of at least one of the alkali metal oxides Na 2 O, K 2 O, and Li 2 O, 20-80% SiO 2 , 2- 25% of at least one oxide selected from the group consisting of Ag 2 O, CuO, CdO, CaO, SrO, BaO, CoO, PbO, MgO, HgO, NiO, ZnO, and MnO, 10-50% carbon, and 0-50% of a filler pigment, the total of silica and pigment being 45-85%.
Claim 3
Dependent Claim
27 words
A cathode ray tube according to claim 1 wherein the electrically conductive coating connects the contact button in the wall of the funnel with the viewing screen.
Claim 4
Dependent Claim
25 words
A cathode ray tube according to claim 2 wherein the electrically conductive coating contains 25-40% carbon and has a resistivity of not over 5,000 ohms/square.
Claim 5
Dependent Claim
27 words
A cathode ray tube according to claim 1 wherein the electrically conducting coating extends over the yoke section connecting the funnel and neck portions of the tube.
Claim 6
Dependent Claim
30 words
A cathode ray tube according to claim 4 wherein the electrically conducting coating contains 10-20% carbon and has a resistivity on the order of 10 5 to 10 6 ohms/square.
Claim 7
Dependent Claim
20 words
A cathode ray tube according to claim 1 wherein the electrically conducting coating contains 25-45% of an inorganic filler pigment.
Claim 8
Dependent Claim
23 words
A cathode ray tube according to claim 1 wherein the electrically conducting coating contains K 2 O as the alkali metal oxide component.
Claim 9
Dependent Claim
21 words
A cathode ray tube according to claim 1 wherein the electrically conducting coating contains ZnO as the divalent metal oxide component.
References Cited (Backward Citations)
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Cited
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Cited
US2223924A
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US2699510A
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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) | 1980-10-03 | 1981-04-04 | 1981-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-03 | 1985-04-04 | 1985-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-03 | 1989-04-04 | 1989-10-04 | $7700.00 | Window Closed / Lapsed |