US4289991A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluorescent lamp with a low reflectivity protective film of aluminum oxide
Assignee: Osram Sylvania Inc
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Filing: 1977-09-06
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Granted: 1981-09-15
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Expires: 1997-09-06
Abstract
Abstract The light output and lumen maintenance of fluorescent lamps with or without a conductive film, are improved by coating the glass envelope or the conductive glass envelope with a thin transparent film of Al 2 O 3 . The alumina film is obtained from a coating of a binderless suspension of submicron size Al 2 O 3 particles in lightly acidified water and has a thickness of 20 to 80 nanometers.
Inventors
- 👤 Willy P. Schreurs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:59
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/30; H01J61/35
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
63 words
In a fluorescent lamp comprising a sealed glass envelope containing a fill including low pressure mercury vapor, the improvement which comprises an antireflective film of aluminum oxide disposed on an electroconductive layer adhering to the inner surface of the glass envelope, wherein the thickness of the antireflective film is such as to increase both initial light output and lumen maintenance of the lamp.
Claim 2
Dependent Claim
63 words
In a fluorescent lamp comprising a sealed glass envelope containing a fill including low pressure mercury vapor, the improvement which comprises an antireflective film of aluminum oxide disposed on an electroconductive layer adhering to the inner surface of the glass envelope, wherein the thickness of the antireflective film is such as to increase both initial light output and lumen maintenance of the lamp.
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) | 1984-09-14 | 1985-03-16 | 1985-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-14 | 1989-03-16 | 1989-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-14 | 1993-03-16 | 1993-09-15 | $7700.00 | Window Closed / Lapsed |