US4639637A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arc discharge lamp having improved lumen maintenance
Assignee: Osram Sylvania Inc
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Filing: 1981-01-27
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Granted: 1987-01-27
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Expires: 2001-01-27
Abstract
Abstract Lumen maintenance of fluorescent lamps is improved by overcoating the phosphor layer with a coating of submicron size alumina having a weight greater than 160 micrograms per square centimeter.
Inventors
- 👤 Fred R. Taubner
- 👤 Joseph A. Roy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:06
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/30; H01J61/35; H01J61/38; H01J61/42
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
69 words
An arc discharge lamp having a light emitting envelope containing an ionizable medium which includes mercury vapor and having electrodes sealed into the ends thereof; and a layer of phosphor on the interior surface of said envelope, the improvement comprising: a layer of submicron size alumina overlying said layer of phosphor, the weight of said alumina being in the range of about 300 to 500 micrograms per square centimeter.
Claim 2
Dependent Claim
69 words
An arc discharge lamp having a light emitting envelope containing an ionizable medium which includes mercury vapor and having electrodes sealed into the ends thereof; and a layer of phosphor on the interior surface of said envelope, the improvement comprising: a layer of submicron size alumina overlying said layer of phosphor, the weight of said alumina being in the range of about 300 to 500 micrograms per square centimeter.
Claim 3
Dependent Claim
14 words
The discharge lamp of claim 1 wherein said discharge lamp is a fluorescent lamp.
Claim 4
Dependent Claim
13 words
The discharge lamp of claim 1 wherein said phosphor is a calcium halophosphate.
Claim 5
Dependent Claim
64 words
An arc discharge lamp having a light emitting envelope containing an ionizable medium which includes mercury vapor and having electrodes sealed into the ends thereof; and a layer of phosphor on the interior surface of said envelope, the improvement comprising: a layer of submicron size alumina overlying said layer of phosphor, the weight of said alumina being greater than 200 micrograms per square centimeter.
Claim 6
Dependent Claim
64 words
An arc discharge lamp having a light emitting envelope containing an ionizable medium which includes mercury vapor and having electrodes sealed into the ends thereof; and a layer of phosphor on the interior surface of said envelope, the improvement comprising: a layer of submicron size alumina overlying said layer of phosphor, the weight of said alumina being greater than 200 micrograms per square centimeter.
Claim 7
Dependent Claim
27 words
The discharge lamp of claim 4 wherein the weight of said alumina is in the range of greater than 200 to about 500 micrograms per square centimeter.
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) | 1990-01-26 | 1990-07-28 | 1991-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-26 | 1994-07-28 | 1995-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-26 | 1998-07-28 | 1999-01-27 | $7700.00 | Window Closed / Lapsed |