US4303848A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Discharge lamp and method of making same
Assignee: Toshiba Corp
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Filing: 1979-08-29
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Granted: 1981-12-01
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Expires: 1999-08-29
Abstract
Abstract In a discharge lamp comprising a sintered electrode comprising a high temperature melting metal such as tungsten, molybdenum, tantalum or mixtures thereof as a main ingredient of the sintered electrode and an electron emissive material of an alkaline earth metal or compound thereof, the sintered electrode further comprising at least one oxide of a metal selected from the group consisting of yttrium, zirconium and aluminum.
Inventors
- 👤 Kenichi Shimizu
- 👤 Akihiro Kamiya
- 👤 Shu Yamazaki
- 👤 Riozo Akiyama
- 👤 Teruji Makuuchi
- 👤 Shiichiro Yoshizaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:54
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/04
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
104 words
A discharge lamp comprising a sintered electrode comprising a high temperature melting metal selected from the group consisting of tungsten, molybdenum, tantalum and mixtures thereof as a main component and at least one oxide of a metal selected from the group consisting of yttrium, zirconium, aluminum and mixtures thereof, said oxide comprising from about 3% to about 30% by weight of said sintered electrode, and an alkaline earth metal compound as an electron emitting material sintered together with said high temperature melting metal and said oxide, said alkaline earth metal compound comprising from about 5% to about 40% by weight of said sintered electrode.
Claim 2
Dependent Claim
104 words
A discharge lamp comprising a sintered electrode comprising a high temperature melting metal selected from the group consisting of tungsten, molybdenum, tantalum and mixtures thereof as a main component and at least one oxide of a metal selected from the group consisting of yttrium, zirconium, aluminum and mixtures thereof, said oxide comprising from about 3% to about 30% by weight of said sintered electrode, and an alkaline earth metal compound as an electron emitting material sintered together with said high temperature melting metal and said oxide, said alkaline earth metal compound comprising from about 5% to about 40% by weight of said sintered electrode.
Claim 3
Dependent Claim
19 words
A discharge lamp according to claim 1 wherein said alkaline earth metal compound comprises an alkaline earth metal carbonate.
Claim 4
Independent Claim
67 words
The method of manufacturing a sintered electrode used for a discharge lamp comprising: (1) forming a mixture of a high temperature melting metal powder and at least one oxide selected from the group consisting of yttrium, zirconium and aluminum, (2) adding an alkaline earth metal compound to said mixture from (1); (3) compacting said mixture from (2) to form an article, and (4) sintering said compacted article.
Claim 5
Independent Claim
67 words
The method of manufacturing a sintered electrode used for a discharge lamp comprising: (1) forming a mixture of a high temperature melting metal powder and at least one oxide selected from the group consisting of yttrium, zirconium and aluminum, (2) adding an alkaline earth metal compound to said mixture from (1); (3) compacting said mixture from (2) to form an article, and (4) sintering said compacted article.
Claim 6
Dependent Claim
30 words
The method according to claim 3 wherein mixing step (1) includes the step of: forming agglomerates of the powder mixture with an organic binder, crushing the agglomerates to form granules.
Claim 7
Dependent Claim
18 words
Method according to claim 4 wherein step (2) includes the step of granulating said alkaline earth metal compound.
Claim 8
Dependent Claim
14 words
Method according to claim 5 wherein said alkaline earth metal compound is barium-calcium carbonate.
References Cited (Backward Citations)
JPS5174480A
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US4052634A
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US4097762A
Cited
US4136227A
Cited
US4152619A
Cited
US4152620A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-11-30 | 1985-06-01 | 1985-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-30 | 1989-06-01 | 1989-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-30 | 1993-06-01 | 1993-12-01 | $7700.00 | Window Closed / Lapsed |