Patent US3885181A successfully refreshed from Google Patents.
US3885181A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric discharge lamps
Assignee: Ledvance Ltd
•
Filing: 1973-04-09
•
Granted: 1975-05-20
•
Expires: 1993-04-09
Abstract
Abstract In a tubular high pressure electric discharge lamp, for example a high pressure sodium lamp, the conformation of the interior and/or exterior longitudinal surface of the tubular discharge envelope wall is such as to produce a non-circular cross-section of the interior and/or exterior of the envelope, the configuration of the envelope being such as to give an asymmetric polar distribution of the light emitted from the lamp as a whole. The envelope may be of uniform wall thickness, both the exterior and the interior being of similar non-circular cross-section, for example elliptical, ovate or substantially rectangular. Alternatively, the wall may be of varying thickness around the circumference, such that one or more optical elements, for example lenses, prisms or multiple prisms, are incorporated in the wall structure, the internal and external cross-sections of the tube thus being of different shape, and possibly one or the other being circular. The preferred material for the fabrication of the envelope is transparent crystalline corundum.
Inventors
- 👤 Evan Herbert Nelson
- 👤 Sydney Alfred Richard Rigden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:55
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/30; H01J61/33
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
140 words
A high pressure electric discharge lamp comprising a tubular discharge envelope formed of transparent crystalline corundum, with a pair of electrodes disposed coaxially within said envelope and carried respectively by closure means closing each end of the envelope, wherein at least one of the interior and exterior longitudinal surfaces of the tubular discharge envelope wall is of nonuniform conformation around the circumference such that in any cross-section of the envelope the distance of said surface from the longitudinal axis of the envelope is less in at least one region of the cross-section than in the remainder of the cross-section, the cross-sectional conformation of the envelope wall being uniform throughout the length of the envelope, whereby the polar distribution of light emitted from the lamp as a whole, in operation of the lamp, is non-uniform around the circumference of the envelope.
Claim 2
Dependent Claim
140 words
A high pressure electric discharge lamp comprising a tubular discharge envelope formed of transparent crystalline corundum, with a pair of electrodes disposed coaxially within said envelope and carried respectively by closure means closing each end of the envelope, wherein at least one of the interior and exterior longitudinal surfaces of the tubular discharge envelope wall is of nonuniform conformation around the circumference such that in any cross-section of the envelope the distance of said surface from the longitudinal axis of the envelope is less in at least one region of the cross-section than in the remainder of the cross-section, the cross-sectional conformation of the envelope wall being uniform throughout the length of the envelope, whereby the polar distribution of light emitted from the lamp as a whole, in operation of the lamp, is non-uniform around the circumference of the envelope.
Claim 3
Dependent Claim
41 words
A lamp according to claim 1 wherein the interior and exterior surfaces of the envelope wall are of parallel conformation, so that the wall thickness is uniform and both the exterior and interior of the envelope are of similar cross-sectional conformation.
Claim 4
Dependent Claim
47 words
A lamp according to claim 2 wherein the cross-section of the envelope has one of the shapes consisting of an ellipse, an ovoid, and substantially a rectangle, whereby the maximum emission of light from the lamp in operation is obtained from two opposite regions in said cross-section.
Claim 5
Dependent Claim
45 words
A lamp according to claim 1 wherein the interior and exterior surfaces of the envelope are of different conformation, so that in the cross-section of the envelope the wall is of varying thickness and at least one optical element is incorporated in the wall structure.
Claim 6
Dependent Claim
18 words
A lamp according to claim 4 wherein at least one lens is incorporated in the envelope wall structure.
Claim 7
Dependent Claim
49 words
A lamp according to claim 5 wherein a lens is incorporated in each of two opposite sides of the envelope wall, whereby the maximum emission of light from the lamp in operation is obtained from the two opposite regions in the cross-section of the envelope which comprise said lenses.
Claim 8
Dependent Claim
18 words
A lamp according to claim 4 wherein at least one prism is incorporated in the envelope wall structure.
Claim 9
Dependent Claim
49 words
A lamp according to claim 7 wherein a prism is incorporated in each of two opposite sides of the envelope wall, whereby the maximum emission of light from the lamp in operation is obtained from the two opposite regions in the cross-section of the envelope which comprise said prisms.
Claim 10
Dependent Claim
19 words
A lamp according to claim 4 wherein at least one multiple prism is incorporated in the envelope wall structure.
Claim 11
Dependent Claim
51 words
A lamp according to claim 9 wherein a multiple prism is incorporated in each of two opposite sides of the envelope wall, whereby the maximum emission of light from the lamp in operation is obtained from the two opposite regions in the cross-section of the envelope which comprise said multiple prisms.
References Cited (Backward Citations)
US1858497A
Cited
US2362171A
Cited
US2482421A
Cited
US2775718A
Cited
US3119040A
Cited
US3243635A
Cited
US3428846A
Cited
US3385463A
Cited
US3474277A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |