US3764866A
Expired / Lapsed
US
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Corona generator
Assignee: Xerox Corp
•
Filing: 1971-12-23
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Granted: 1973-10-09
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Expires: 1991-12-23
Abstract
Abstract A tungsten wire corona generator having a stable coating thereon for providing the generator with an extremely long life and a stable output.
Inventors
- 👤 J Bonaventura
- 👤 R Harshbarger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:51
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/02; G03G15/0291; H; H05; H05F; H05F3/00; H05F3/04
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
21 words
The apparatus of claim 1 wherein the tungsten electrode is formed of a material that is at least 99 percent pure.
Claim 2
Dependent Claim
18 words
The apparatus of claim 2 wherein the oxide formed on said electrode includes the oxides WO2 and W18O49.
Claim 3
Dependent Claim
21 words
The apparatus of claim 3 wherein the oxide coating is of a thickness of about or greater than one-half a micron.
Claim 4
Independent Claim
64 words
The method of producing a corona emitting electrode which is capable of producing a stable output over an extended period of time including providing an electrode of relatively pure tungsten, and oxidizing said electrode by heating the electrode in air to a temperature at or about 600*C for a period of time sufficient to coat the corona generating surface with a tungsten oxide layer.
Claim 5
Dependent Claim
18 words
The method of claim 5 wherein the coating formed on said electrode includes the oxides WO2 and W18O49.
Claim 6
Dependent Claim
22 words
The method of Claim 5 wherein said electrode is precleaned prior to oxidation to remove impurities from the surface of said electrode.
Claim 7
Dependent Claim
19 words
The method of claim 5 wherein said electrode is heated at or above 600*C for at least 10 minutes.
Claim 8
Dependent Claim
22 words
The method of claim 5 wherein said oxide coating is formed to a thickness which is at least one-half of a micron.
Claim 9
Dependent Claim
21 words
The method of claim 5 wherein said electrode is formed of a tungsten material which is at least 99 percent pure.
Claim 10
Independent Claim
84 words
The method of producing a corona emitting electrode that is capable of producing a stable output over an extended period of time including producing an elongated tungsten wire formed of a relatively pure material, cleaning the surface of said tungsten wire to remove impurities therefrom, oxidizing said tungsten wire by heating said wire in air to a temperature at or above 600*C for a period of time sufficient to form an oxide coating thereon which is between one-half and three and one-half microns thick.
Claim 11
Dependent Claim
19 words
The method of claim 11 wherein the oxide coating formed on said wire includes the oxides WO2 and W18O49.
References Cited (Backward Citations)
US2922883A
Cited
US3537914A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |