Patent US4459507A successfully refreshed from Google Patents.
US4459507A
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Fluorescent lamps having improved maintenance and method of making same
Assignee: Osram Sylvania Inc
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Filing: 1982-02-18
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Granted: 1984-07-10
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Expires: 2002-02-18
Abstract
Abstract Lumen maintenance of fluorescent lamps is improved by applying over the phosphor of the lamps a vapor deposited film of yttrium oxide having a purity of 99.99%. The vapor is generated by electron beam bombardment of an yttrium oxide target and the film is most efficacious when applied to a thickness of from about 120 to about 600 angstroms.
Inventors
- 👤 John M. Flaherty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:39
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/30; H01J61/35
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
50 words
A fluorescent lamp comprising: a tubular, hermetically sealed, glass envelope; electrodes sealed in the ends of said envelope; an arc generating and sustaining medium including mercury with said envelope; a phosphor coating on the interior surface of said envelope; and a maintenance improving coating of yttrium oxide overlying said phosphor.
Claim 2
Dependent Claim
50 words
A fluorescent lamp comprising: a tubular, hermetically sealed, glass envelope; electrodes sealed in the ends of said envelope; an arc generating and sustaining medium including mercury with said envelope; a phosphor coating on the interior surface of said envelope; and a maintenance improving coating of yttrium oxide overlying said phosphor.
Claim 3
Dependent Claim
20 words
The lamp of claim 1 wherein said yttrium oxide has a thickness of from about 120 angstroms to 600 angstroms.
Claim 4
Dependent Claim
13 words
The lamp of claim 2 wherein said phosphor is manganese activated zinc orthosilicate.
Claim 5
Dependent Claim
14 words
The lamp of claim 3 wherein said yttrium oxide has a purity of 99.99%.
Claim 6
Independent Claim
33 words
The method of making a fluorescent lamp having improved maintenance which comprises the steps of: coating a tubular glass envelope with a phosphor; and applying over said phosphor a film of yttrium oxide.
Claim 7
Independent Claim
33 words
The method of making a fluorescent lamp having improved maintenance which comprises the steps of: coating a tubular glass envelope with a phosphor; and applying over said phosphor a film of yttrium oxide.
Claim 8
Dependent Claim
30 words
The method of claim 5 wherein said film is deposited by electron beam vaporization of an yttrium oxide target and subsequent deposition of the vapor so generated upon said phosphor.
Claim 9
Dependent Claim
22 words
The method of claim 6 wherein said film is deposited to a thickness of from about 120 angstroms to about 600 angstroms.
Claim 10
Dependent Claim
16 words
The method of claim 7 wherein said yttrium oxide target has a purity of about 99.99%.
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) | 1987-07-10 | 1988-01-09 | 1988-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-10 | 1992-01-09 | 1992-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-10 | 1996-01-09 | 1996-07-10 | $7700.00 | Window Closed / Lapsed |