Patent US3791546A successfully refreshed from Google Patents.
US3791546A
Expired / Lapsed
US
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Cathode-ray tube having conductive internal coating comprised of iron oxide and graphite
Assignee: RCA Licensing Corp
•
Filing: 1971-11-26
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Granted: 1974-02-12
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Expires: 1991-11-26
Abstract
Abstract A cathode-ray tube having a conductive internal coating comprised of iron oxide, graphite, and an alkali silicate on the interior walls of the tube.
Inventors
- 👤 J Maley
- 👤 D Bartch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:42
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/86; H01J29/88; H01J2229/00; H01J2229/88; H01J2229/882
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
36 words
The tube defined in claim 1 wherein the coating consists essentially of about 100 weight parts graphite particles, 200 to 600 weight parts iron oxide particles and about 50 to 150 weight parts alkali silicate binder.
Claim 2
Dependent Claim
14 words
The tube defined in claim 2 wherein said alkali silicate binder is sodium silicate.
Claim 3
Dependent Claim
108 words
In a television picture tube comprising an evacuated glass envelope including a neck for housing an electron gun, a faceplate panel opposite the neck, and a funnel providing a closed transition between said neck and said panel, the improvement comprising a coating adhered to at least a portion of the interior walls of said funnel and neck, said coating consisting essentially of about 100 weight parts graphite particles, about 200 to 600 weight parts iron oxide particles and about 50 to 150 weight parts alkali silicate binder, said coating being of such thickness as to provide a point-to-point electrical resistance of about 200 to 2,000 ohms per inch.
Claim 4
Dependent Claim
25 words
The tube defined in claim 4 wherein said electrical resistance is about 200 to 300 ohms per inch and the iron oxide is ferric oxide.
Claim 5
Dependent Claim
37 words
The tube defined in claim 5 wherein said coating consists essentially of about 100 weight parts graphite particles, about 200 to 220 weight parts iron oxide particles, and about 125 to 150 weight parts alkali silicate binder.
Claim 6
Dependent Claim
13 words
The tube defined in claim 6 wherein said alkali silicate is sodium silicate.
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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) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |