US3842304A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High-pressure gas discharge lamp
Assignee: US Philips Corp
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Filing: 1973-04-30
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Granted: 1974-10-15
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Expires: 1993-04-30
Abstract
Abstract A high-pressure gas discharge lamp having a discharge vessel provided with materials, which during operation of the lamp are present in a gaseous and/or vapor state in which at least one of these materials during operation of the lamp provides a saturated vapor, and having an electrode placed at one end of the discharge vessel in which the discharge vessel at said end is provided with an external coating. The coating consists of a first film located on the wall of the discharge vessel and comprising a black or dark grey material having a high melting point and low vapor pressure (for example, carbon), and a second film located on the first film and comprising a white or substantially white material having a high melting point and a low vapor pressure (for example, zirconium oxide).
Inventors
- 👤 L Beyer
- 👤 C Jacobs
- 👤 G Siebers
- 👤 G Cornelissen
- 👤 A Driessen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 00:27
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/30; H01J61/35
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
128 words
In a high-pressure gas discharge lamp comprising a discharge vessel provided with materials which during operation of the lamp are present in a gaseous and/or vapor state, at least one of said materials during operation of the lamp supplying a saturated vapor, said lamp provided with an electrode placed at one end of the discharge vessel, the discharge vessel at said end being provided with an external coating, said coating consisting of a first film located on the wall of the discharge vessel and comprising a black or dark-grey material having a high melting point and a low vapor pressure, and of a second film located on the first film and comprising a white or substantially white material having a high melting point and a low vapor pressure.
Claim 2
Dependent Claim
128 words
In a high-pressure gas discharge lamp comprising a discharge vessel provided with materials which during operation of the lamp are present in a gaseous and/or vapor state, at least one of said materials during operation of the lamp supplying a saturated vapor, said lamp provided with an electrode placed at one end of the discharge vessel, the discharge vessel at said end being provided with an external coating, said coating consisting of a first film located on the wall of the discharge vessel and comprising a black or dark-grey material having a high melting point and a low vapor pressure, and of a second film located on the first film and comprising a white or substantially white material having a high melting point and a low vapor pressure.
Claim 3
Dependent Claim
41 words
A high-pressure gas discharge lamp as claimed in claim 1, wherein the first film mainly consists of at least one of the materials carbon, carbides, silicates and borates and that the second film mainly consists of at least one ceramic oxide.
Claim 4
Dependent Claim
27 words
A high-pressure gas discharge lamp as claimed in claim 1, wherein the first film mainly consists of carbon and the second film mainly consists of zirconium oxide.
Claim 5
Dependent Claim
35 words
A high-pressure gas discharge lamp as claimed in claim 1 wherein the coating is located around the electrode and extends to not more than 5 mms beyond the end of the electrode facing the discharge.
Claim 6
Dependent Claim
63 words
A high-pressure gas discharge lamp as claimed in claim 1 in which the discharge vessel consists of quartz glass or hard glass and is filled with mercury, one or more rare gases and one or more metal halides, wherein the coating is located around the electrode and extends to not more than 2 mms beyond the end of the electrode facing the discharge.
Claim 7
Dependent Claim
86 words
A method of providing an external coating on a high-pressure gas discharge lamp as claimed in claim 3 wherein the end of the discharge vessel in the vicinity of the electrode is coated with a first film of a graphite suspension, the first film being coated after drying with a second film consisting of a suspension of zirconium oxide in a suspension agent comprising a solvent and a binder, the coating thus obtained after drying being heated in air at a temperature of 250* - 500*C.
Claim 8
Dependent Claim
41 words
A method as claimed in claim 6, wherein a colloidal solution of graphite in water is used for the first film and a suspension of zirconium oxide in an organic solvent comprising an organic binder is used for the second film.
References Cited (Backward Citations)
US3513344A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-14 | 1978-04-15 | 1978-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-14 | 1982-04-15 | 1982-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-14 | 1986-04-15 | 1986-10-15 | $7700.00 | Window Closed / Lapsed |