US4605881A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High pressure sodium iodide arc lamp with excess iodine
Assignee: General Electric Co
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Filing: 1984-11-29
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Granted: 1986-08-12
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Expires: 2004-11-29
Abstract
Abstract Iodine in excess of sodium-iodide stoichiometry is used in the fill for a sodium iodide arc lamp which also includes sodium iodide and xenon buffer gas. The presence of free sodium near the arc tube walls is eliminated and efficacy is improved.
Inventors
- 👤 James T. Dakin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:54
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/12; H01J61/125; H01J61/82; H01J61/825
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
74 words
In a high pressure sodium iodide arc lamp having an arc tube for containing an arc discharge, an arc tube fill comprising sodium iodide; xenon buffer gas in an amount providing a xenon partial pressure in the range of about 100 torr and higher at room temperature; and iodine in sufficient quantity to reduce, the partial pressure of sodium at the walls of said arc tube to substantially zero during operation of said lamp.
Claim 2
Dependent Claim
74 words
In a high pressure sodium iodide arc lamp having an arc tube for containing an arc discharge, an arc tube fill comprising sodium iodide; xenon buffer gas in an amount providing a xenon partial pressure in the range of about 100 torr and higher at room temperature; and iodine in sufficient quantity to reduce, the partial pressure of sodium at the walls of said arc tube to substantially zero during operation of said lamp.
Claim 3
Dependent Claim
35 words
The lamp of claim 1 wherein said sodium iodide is present in sufficient quantity to provide a sodium pressure during operation of said lamp in said arc discharge of about 10 to about 100 torr.
Claim 4
Dependent Claim
40 words
The lamp of claim 2 wherein said quantity of iodine equals an amount which provides an iodine partial pressure of 10 to 50 torr in excess of overall sodium-iodine stoichiometry in the presence of an arc within said arc tube.
Claim 5
Dependent Claim
17 words
The lamp of claim 1 wherein said iodine is derived from mercury iodide included in said fill.
Claim 6
Dependent Claim
105 words
A high intensity arc discharge lamp comprising: an outer light transmissive envelope; a light transmissive arc discharge tube situated within said envelope and having electrodes at opposite ends thereof; means to provide electrical connection to said electrodes; sodium iodide disposed within said arc tube; xenon buffer gas disposed within said arc tube in an amount providing a xenon partial pressure in the range of about 100 torr and higher at room temperature; and iodine disposed within said arc tube in a sufficient quantity to reduce the partial pressure of sodium at the walls of said arc tube to substantially zero during operation of said lamp.
Claim 7
Dependent Claim
105 words
A high intensity arc discharge lamp comprising: an outer light transmissive envelope; a light transmissive arc discharge tube situated within said envelope and having electrodes at opposite ends thereof; means to provide electrical connection to said electrodes; sodium iodide disposed within said arc tube; xenon buffer gas disposed within said arc tube in an amount providing a xenon partial pressure in the range of about 100 torr and higher at room temperature; and iodine disposed within said arc tube in a sufficient quantity to reduce the partial pressure of sodium at the walls of said arc tube to substantially zero during operation of said lamp.
Claim 8
Dependent Claim
35 words
The lamp of claim 5 wherein said sodium iodide is present in sufficient quantity to provide a sodium pressure during operation of said lamp in said arc discharge of about 10 to about 100 torr.
Claim 9
Dependent Claim
41 words
The lamp of claim 6 wherein said quantity of iodine equals an amount which provides an iodine partial pressure of about 10 to 50 torr in excess of overall sodium-iodine stoichiometry in the presence of an arc within said arc tube.
References Cited (Backward Citations)
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Cited
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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) | 1989-08-11 | 1990-02-10 | 1990-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-11 | 1994-02-10 | 1994-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-11 | 1998-02-10 | 1998-08-12 | $7700.00 | Window Closed / Lapsed |