US4387319A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Metal halide lamp containing ScI3 with added cadmium or zinc
Assignee: General Electric Co
•
Filing: 1981-03-30
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Granted: 1983-06-07
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Expires: 2001-03-30
Abstract
Abstract A high intensity metal halide discharge lamp has a fill comprising mercury, sodium iodide and scandium triiodide plus an inert starting gas. Cadmium or zinc may be added in a molar ratio relative to ScI 3 within the range of 0.04 to 1.0 to achieve a lowering in color temperature of several hundred degrees Kelvin at the cost of a minor decrease in lumens which is offset by an improvement in maintenance.
Inventors
- 👤 Philip J. White
- 👤 William H. Lake
- 👤 Robert H. Springer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:29
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/12; H01J61/18
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
107 words
A miniature high intensity metal halide arc discharge lamp comprising an envelope of fused silica, defining a volume not exceeding 1 cubic centimeter, inleads sealed into said envelope and electrically connected to spaced tungsten electrodes positioned to define an arc gap therein not exceeding 1 centimeter, a discharge sustaining filling in said envelope-comprising mercury, sodium iodide and scandium triiodide plus an inert starting gas, said envelope containing virtually no thorium except such as may be introduced through the use of thoriated tungsten for the electrodes, and cadmium or zinc in said envelope in a molar ratio relative to ScI 3 in the range of 0.04 to 1.0.
Claim 2
Dependent Claim
107 words
A miniature high intensity metal halide arc discharge lamp comprising an envelope of fused silica, defining a volume not exceeding 1 cubic centimeter, inleads sealed into said envelope and electrically connected to spaced tungsten electrodes positioned to define an arc gap therein not exceeding 1 centimeter, a discharge sustaining filling in said envelope-comprising mercury, sodium iodide and scandium triiodide plus an inert starting gas, said envelope containing virtually no thorium except such as may be introduced through the use of thoriated tungsten for the electrodes, and cadmium or zinc in said envelope in a molar ratio relative to ScI 3 in the range of 0.04 to 1.0.
Claim 3
Dependent Claim
33 words
A lamp as in claim 1 wherein the NaI concentration is in the range of 0.005 to 0.05 gm/cc and the ScI 3 concentration is in the range of 0.0008 to 0.008 gm/cc.
Claim 4
Dependent Claim
19 words
A lamp as in claim 2 wherein the mercury concentration is in the range of 0.015 to 0.05 gms/cc.
Claim 5
Dependent Claim
21 words
A lamp as in claim 3 wherein the molar ratio of Cd or Zn relative to ScI 3 is approximately 0.5.
References Cited (Backward Citations)
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Cited
US3959682A
Cited
US4171498A
Cited
US4161672A
Cited
US4199701A
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US4245175A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-06-06 | 1986-12-06 | 1987-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-06 | 1990-12-06 | 1991-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-06 | 1994-12-06 | 1995-06-07 | $7700.00 | Window Closed / Lapsed |