US4146813A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High-pressure sodium vapor discharge lamp
Assignee: US Philips Corp
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Filing: 1978-03-30
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Granted: 1979-03-27
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Expires: 1998-03-30
Abstract
Abstract The invention relates to a high-pressure sodium vapor discharge lamp comprising a discharge tube containing sodium and xenon. In accordance with the invention the inside diameter of the discharge tube is below 5 mm and greater than 1 mm. In addition the xenon pressure is relatively high in the operating condition of the lamp which -- together with a pressure of the sodium in a given range -- can result in a high luminous efficacy of the lamp.
Inventors
- 👤 Johannes A. J. M. van Vliet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:01
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/12; H01J61/18; H01J61/22
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
115 words
A high-pressure sodium vapour discharge lamp comprising a discharge tube containing xenon as well as sodium, the discharge tube having a circle-cylindrical shape, the discharge tube being provided at each end with a respective internal electrode, and wherein P.sub.xenon > P.sub.sodium where P xenon represents the pressure in Torr of the xenon in the discharge tube at 300° Kelvin and P sodium represents the sodium vapour pressure in Torr in the discharge tube during the operating condition of the lamp, characterized in that 240/√d < P.sub.sodium < 360/√d and 1.25 < P.sub.xenon /P.sub.sodium < 6 and in that 1 < d < 5 where d is the inside diameter (in mm) of the discharge tube.
Claim 2
Dependent Claim
115 words
A high-pressure sodium vapour discharge lamp comprising a discharge tube containing xenon as well as sodium, the discharge tube having a circle-cylindrical shape, the discharge tube being provided at each end with a respective internal electrode, and wherein P.sub.xenon > P.sub.sodium where P xenon represents the pressure in Torr of the xenon in the discharge tube at 300° Kelvin and P sodium represents the sodium vapour pressure in Torr in the discharge tube during the operating condition of the lamp, characterized in that 240/√d < P.sub.sodium < 360/√d and 1.25 < P.sub.xenon /P.sub.sodium < 6 and in that 1 < d < 5 where d is the inside diameter (in mm) of the discharge tube.
Claim 3
Dependent Claim
58 words
A high-pressure sodium vapour discharge lamp as claimed in claim 1, characterized in that 2.5 √W/V < d < 3.1 √W/V where W represents the power in watts of the discharge tube in the operating condition of the lamp; and V is the operating voltage in volts of that discharge tube in the operating condition of the lamp.
Claim 4
Dependent Claim
36 words
A high-pressure sodium vapour discharge lamp as claimed in claim 2, characterized in that 0.54 √W.V. < A < 0.66 √W.V. where A represents the spacing in mm between the two electrodes of the discharge tube.
References Cited (Backward Citations)
US4039880A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-26 | 1982-09-25 | 1983-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-26 | 1986-09-25 | 1987-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-26 | 1990-09-25 | 1991-03-27 | $7700.00 | Window Closed / Lapsed |