US3716743A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High-pressure metal-vapor discharge tube
Assignee: Panasonic Holdings Corp
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Filing: 1970-08-28
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Granted: 1973-02-13
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Expires: 1990-08-28
Abstract
Abstract In a discharge tube of saturated metal vapor pressure type containing high-pressure gaseous or vaporized metals, the temperature of the coolest points existing at both ends of the discharge tube can be raised by forming a layer or layers of a metal or metals of high melting point, low vapor pressure and good thermal conductivity, such as niobium, on the outer wall at the ends of the discharge tube; thereby, providing better radiant emission, especially higher color temperature and an improved color rendering property compared with conventional high-pressure metal-vapor discharge tubes. The discharge tube of the abovementioned construction can be manufactured easily and has a longer life under burning conditions corresponding to those for conventional type high-pressure metal-vapor discharge tubes.
Inventors
- 👤 H Mizuno
- 👤 S Kimura
- 👤 H Akutsu
- 👤 Y Watarai
- 👤 S Baba
- 👤 H Yamazaki
- 👤 T Okamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:00
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/04; H01J61/045
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
135 words
High-pressure metal-vapor discharge tube comprising a sealed tubular enclosure of transparent polycrystalline high-density ceramic, a pair of electrodes having rear tip and front tip portions, each of said electrodes being enclosed near a respective end of said enclosure, a starting rare gas, and a small amount of mercury plus at least one ionizable medium of alkali metal sufficient to form a saturated metal vapor confined in said enclosure, and characterized in that: layers of thermally conductive, heat durable metal are formed on the outer wall of the tubular enclosure proximate to the ends thereof, said layers extending from the end of the tubular enclosure beyond the rear tip of the electrode to a position of no more than 5 mm from the front tip of the electrode toward the central part of the tubular enclosure.
Claim 2
Dependent Claim
135 words
High-pressure metal-vapor discharge tube comprising a sealed tubular enclosure of transparent polycrystalline high-density ceramic, a pair of electrodes having rear tip and front tip portions, each of said electrodes being enclosed near a respective end of said enclosure, a starting rare gas, and a small amount of mercury plus at least one ionizable medium of alkali metal sufficient to form a saturated metal vapor confined in said enclosure, and characterized in that: layers of thermally conductive, heat durable metal are formed on the outer wall of the tubular enclosure proximate to the ends thereof, said layers extending from the end of the tubular enclosure beyond the rear tip of the electrode to a position of no more than 5 mm from the front tip of the electrode toward the central part of the tubular enclosure.
Claim 3
Dependent Claim
34 words
High-pressure metal-vapor discharge tube of claim 1, wherein said thermally conductive metal is a metal selected from a group consisting of titanium, vanadium, rhodium, ruthenium, molybdenum, niobium, tantalum, tungsten, platinum, iridium, rhenium and osmium.
Claim 4
Dependent Claim
32 words
High-pressure metal-vapor discharge tube of claim 2, wherein each said layer of thermally conductive metal is in the form of a metal foil wound around each end part of the tubular enclosure.
Claim 5
Dependent Claim
25 words
High-pressure metal-vapor discharge tube of claim 2, wherein said layers are in the form of a chemically decomposed chemical compound of said thermally conductive metal.
Claim 6
Dependent Claim
21 words
High-pressure metal-vapor discharge tube of claim 2, wherein said layers are in the form of a vacuum deposited thermally conductive metal.
Claim 7
Dependent Claim
19 words
High-pressure metal-vapor Discharge tube of claim 2, wherein said layers are in the form of sputtered thermally conductive metal.
Claim 8
Dependent Claim
44 words
High-pressure metal-vapor discharge tube of claim 1, wherein a pair of end discs is hermetically sealed in the ends of said tubular enclosure, respectively, said pair of electrodes being carried by said end discs, said end discs being formed from a heat durable metal.
Claim 9
Dependent Claim
26 words
High-pressure metal-vapor discharge tube of claim 7, wherein said end discs are formed from a material selected from the group consisting of niobium, tantalum, and molybdenum.
Claim 10
Dependent Claim
142 words
High-pressure metal-vapor discharge tube comprising a sealed tubular enclosure of transparent polycrystalline high-density ceramic, a pair of electrodes, each of which is enclosed near a respective end of said enclosure, a starting rare gas, a small amount of mercury plus at least one ionizable medium of alkali metal sufficient to form a saturated metal vapor confined in said enclosure, and at least one layer of a thermally conductive heat durable metal formed on the outer wall of the tubular enclosure proximate to the ends thereof, each layer being in the form of a metal foil wound around the tubular enclosure, said at least one layer extending from the end of the tubular enclosure beyond the tip of the electrode a distance of no more than 5 mm from the front tip of the electrode toward the central part of the tubular enclosure.
Claim 11
Dependent Claim
142 words
High-pressure metal-vapor discharge tube comprising a sealed tubular enclosure of transparent polycrystalline high-density ceramic, a pair of electrodes, each of which is enclosed near a respective end of said enclosure, a starting rare gas, a small amount of mercury plus at least one ionizable medium of alkali metal sufficient to form a saturated metal vapor confined in said enclosure, and at least one layer of a thermally conductive heat durable metal formed on the outer wall of the tubular enclosure proximate to the ends thereof, each layer being in the form of a metal foil wound around the tubular enclosure, said at least one layer extending from the end of the tubular enclosure beyond the tip of the electrode a distance of no more than 5 mm from the front tip of the electrode toward the central part of the tubular enclosure.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-13 | 1976-08-14 | 1977-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-13 | 1980-08-14 | 1981-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-13 | 1984-08-14 | 1985-02-13 | $7700.00 | Window Closed / Lapsed |