US4894590A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spiral single starting electrode for HID lamps
Assignee: General Electric Co
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Filing: 1988-08-01
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Granted: 1990-01-16
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Expires: 2008-08-01
Abstract
Abstract A single starting electrode is provided for an electrodeless high-intensity-discharge lamp arc of the type having an arc tube situated within the bore of an excitation coil and in the interior of which arc tube is to be provided a plasma arc discharge driven by the excitation coil. The starting electrode is a conductive conical spiral having a narrower end disposed adjacent to one of the arc tube surfaces. A high voltage is formed by induction, as the spiral electrode receives an RF magnetic flux, to cause an electric field to be produced sufficient to create a glow discharge in the arc tube, and cause a rapid transition to a high-current solenoidal discharge to form the discharge plasma responsive to the normal field provided by the excitation coil.
Inventors
- 👤 Harald L. Witting
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:08
CPC Classifications
H; H01; H01J; H01J65/00; H01J65/04; H01J65/042; H01J65/048
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
126 words
A starting electrode for an electrodeless high-intensity-discharge (HID) lamp of the type having an arc tube situated within the bore of an excitation coil and within which arc tube a plasma arc discharge is to be formed and driven by the excitation coil, comprising: a single starting electrode having a spiral shape and positioned, at least during commencement of the plasma arc discharge, with a narrower end adjacent to a selected point on an exterior surface of the arc tube; and means for positioning the electrode with a wider end at a selected location, to place the electrode within magnetic flux, generated by the excitation coil, sufficient to cause creation, at least at said plasma arc discharge commencement, of a glow discharge within the arc tube.
Claim 2
Dependent Claim
126 words
A starting electrode for an electrodeless high-intensity-discharge (HID) lamp of the type having an arc tube situated within the bore of an excitation coil and within which arc tube a plasma arc discharge is to be formed and driven by the excitation coil, comprising: a single starting electrode having a spiral shape and positioned, at least during commencement of the plasma arc discharge, with a narrower end adjacent to a selected point on an exterior surface of the arc tube; and means for positioning the electrode with a wider end at a selected location, to place the electrode within magnetic flux, generated by the excitation coil, sufficient to cause creation, at least at said plasma arc discharge commencement, of a glow discharge within the arc tube.
Claim 3
Dependent Claim
13 words
The starting electrode of claim 1, wherein the spiral is of conical shape.
Claim 4
Dependent Claim
27 words
The starting electrode of claim 2, wherein the spiral electrode further includes an arcuate extension lying in a plane substantially parallel to the arc tube exterior surface.
Claim 5
Dependent Claim
32 words
The starting electrode of claim 3, wherein the curve of said arcuate extension is less than a full circle and greater than a quarter-circle, and said extension substantially abuts against said surface.
Claim 6
Dependent Claim
29 words
The starting electrode of claim 2, wherein said positioning means comprises a conductive member connecting a selected portion of the electrode to an adjacent portion of the excitation coil.
Claim 7
Dependent Claim
18 words
The starting electrode of claim 5, wherein the selected portion is at the wider end of the electrode.
Claim 8
Dependent Claim
39 words
The starting electrode of claim 1, wherein said positioning means includes means, responsive to a selected stimulus, for moving the starting electrode to a location further from said arc tube than the location of the electrode during discharge commencement.
Claim 9
Dependent Claim
27 words
The starting electrode of claim 7, wherein said moving means comprises means for moving the starting electrode responsive to receipt of heat energy from said arc tube.
Claim 10
Dependent Claim
35 words
The starting electrode of claim 6, wherein said heat-energy-responsive moving means is adapted to move the starting electrode back toward the arc tube responsive to cessation of receipt of heat energy from said arc tube.
References Cited (Backward Citations)
US4812702A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-15 | 1993-07-17 | 1994-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-15 | 1997-07-17 | 1998-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-15 | 2001-07-17 | 2002-01-16 | $7700.00 | Window Closed / Lapsed |