US4245175A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Metal halide lamp having lead metal powder to reduce blackening
Assignee: Philips North America LLC
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Filing: 1978-12-08
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Granted: 1981-01-13
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Expires: 1998-12-08
Abstract
Abstract A high pressure metal halide discharge lamp of the sodium-scandium type which has the maintenance thereof improved by the addition of a small quantity of lead metal powder. The lead metal powder is added to the discharge sustaining fill in an amount of from between about 0.4 and 1.2 wt. % of the total amount of discharge sustaining fill.
Inventors
- 👤 William A. McAllister
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:07
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/12; H01J61/18
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
112 words
A high pressure discharge lamp of the metal halide type, said lamp comprising: an outer envelope sealed to a metal base; an arc tube mounted within said outer envelope having a pair of discharge sustaining electrodes at each end thereof, said discharge sustaining electrodes being electrically connected to said metal base; and a discharge sustaining fill, within said arc tube, said discharge sustaining fill including about 2 milligrams of scandium metal, about 16 milligrams of mercuric iodide, about 80 milligrams of sodium iodide, and about 148 milligrams of mercury, and wherein about 2 milligrams of lead metal powder is added to the discharge sustaining fill to enhance the maintenance of said lamp.
Claim 2
Dependent Claim
112 words
A high pressure discharge lamp of the metal halide type, said lamp comprising: an outer envelope sealed to a metal base; an arc tube mounted within said outer envelope having a pair of discharge sustaining electrodes at each end thereof, said discharge sustaining electrodes being electrically connected to said metal base; and a discharge sustaining fill, within said arc tube, said discharge sustaining fill including about 2 milligrams of scandium metal, about 16 milligrams of mercuric iodide, about 80 milligrams of sodium iodide, and about 148 milligrams of mercury, and wherein about 2 milligrams of lead metal powder is added to the discharge sustaining fill to enhance the maintenance of said 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) | 1984-01-13 | 1984-07-14 | 1985-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-13 | 1988-07-14 | 1989-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-13 | 1992-07-14 | 1993-01-13 | $7700.00 | Window Closed / Lapsed |