US4783615A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrodeless high pressure sodium iodide arc lamp
Assignee: General Electric Co
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Filing: 1985-06-26
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Granted: 1988-11-08
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Expires: 2005-06-26
Abstract
Abstract High pressure xenon is used as a buffer gas in an electrodeless sodium iodide arc lamp. Very high efficacies are achieved by using an arc tube with rounded edges and by surrounding a portion of the arc tube with quartz wool. The arc tube may also contain small amounts of mercury iodide.
Inventors
- 👤 James T. Dakin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:56
CPC Classifications
H; H01; H01J; H01J65/00; H01J65/04; H01J65/042; H01J65/048
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
122 words
In an electrodeless metal halide arc lamp having an arc tube for containing an arc discharge, an arc tube fill for producing high luminous efficacy, said fill consisting essentially of: sodium iodide present in a quantity which provides a reservoir of sodium iodide condensate during lamp operation; xenon in a sufficient quantity to provide a partial pressure in the range of about 100 torr and higher at room temperature and to limit the chemical transport of energy from said arc discharge to the walls of said arc tube; and mercury iodide in a quantity less than the quantity of said sodium iodide and in a sufficient quantity to provide an amount of free iodine near said arc tube walls during lamp operation.
Claim 2
Dependent Claim
122 words
In an electrodeless metal halide arc lamp having an arc tube for containing an arc discharge, an arc tube fill for producing high luminous efficacy, said fill consisting essentially of: sodium iodide present in a quantity which provides a reservoir of sodium iodide condensate during lamp operation; xenon in a sufficient quantity to provide a partial pressure in the range of about 100 torr and higher at room temperature and to limit the chemical transport of energy from said arc discharge to the walls of said arc tube; and mercury iodide in a quantity less than the quantity of said sodium iodide and in a sufficient quantity to provide an amount of free iodine near said arc tube walls during lamp operation.
Claim 3
Dependent Claim
96 words
An electrodeless metal halide arc lamp of high luminous efficacy, comprising: a light-transmissive arc tube for containing an arc discharge; and a fill disposed in said arc tube, said fill consisting essentially of sodium iodide present in a quantity which provides a reservoir of sodium iodide condensate during lamp operation and xenon, said xenon being present in a sufficient quantity to provide a partial pressure in the range of about 100 torr and higher at room temperature and to limit the chemical transport of energy from said arc discharge to the walls of said arc tube.
Claim 4
Dependent Claim
96 words
An electrodeless metal halide arc lamp of high luminous efficacy, comprising: a light-transmissive arc tube for containing an arc discharge; and a fill disposed in said arc tube, said fill consisting essentially of sodium iodide present in a quantity which provides a reservoir of sodium iodide condensate during lamp operation and xenon, said xenon being present in a sufficient quantity to provide a partial pressure in the range of about 100 torr and higher at room temperature and to limit the chemical transport of energy from said arc discharge to the walls of said arc tube.
Claim 5
Dependent Claim
16 words
The lamp of claim 2 further comprising excitation means for coupling radio-frequency energy to said fill.
Claim 6
Dependent Claim
44 words
The lamp of claim 2 wherein said fill further consists of mercury iodide in a quantity less than the quantity of said sodium iodide and in a sufficient quantity to provide an amount of free iodine near said arc tube walls during lamp operation.
Claim 7
Dependent Claim
31 words
The lamp of claim 2 wherein said arc tube is cylindrically shaped, the height of said arc tube being less than its outside diameter, said arc tube further having rounded edges.
Claim 8
Dependent Claim
21 words
The lamp of claim 5 further comprising a light-transmissive outer envelope disposed around said arc tube and defining a space therebetween.
Claim 9
Dependent Claim
10 words
The lamp of claim 6 wherein said space is evacuated.
Claim 10
Dependent Claim
18 words
The lamp of claim 6 further including quartz wool disposed in at least a portion of said space.
Claim 11
Dependent Claim
39 words
The lamp of claim 8 wherein said quantity of xenon is sufficient to provide a partial pressure in the range of about 100 torr and higher at room temperature, said fill further consisting of a quantity of mercury iodide.
Claim 12
Dependent Claim
16 words
The lamp of claim 9 further comprising excitation means for coupling radio-frequency energy to said fill.
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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) | 1991-11-08 | 1992-05-09 | 1992-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-08 | 1996-05-09 | 1996-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-08 | 2000-05-09 | 2000-11-08 | $7700.00 | Window Closed / Lapsed |