Patent US4827176A successfully refreshed from Google Patents.
US4827176A
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Metal vapor discharge lamp with radioactively impregnated ceramic material body
Assignee: Toshiba Corp
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Filing: 1987-12-18
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Granted: 1989-05-02
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Expires: 2007-12-18
Abstract
Abstract A metal vapor discharge lamp. The metal vapor discharge lamp includes an enclosed discharge tube having a pair of main electrodes mounted at spaced apart locations therein, the discharge tube including a fill of at least a metal vapor and a starting gas, a radiation source including radioactively impregnated ceramic material having a vitrified radioactive outer protection portion and an outer bulb for enclosing the discharge tube and a circuit for electrically generating an arc between the main electrodes.
Inventors
- 👤 Shinji Inukai
- 👤 Kazuo Honda
- 👤 Akihiro Kamiya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:57
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/54; H01J61/548
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
84 words
A vapor discharge lamp comprising: an enclosed discharge tube having a pair of main electrodes mounted at spaced apart locations therein, the discharge tube including a fill of at least a metal vapor and a starting gas; a radiation source including radioactively impregnated ceramic material having an outer protection portion comprising a vitrified radioactive material; said radiation source being located within said discharge tube; an outer bulb for enclosing the discharge tube; and a circuit for electrically generating an arc between the main electrodes.
Claim 2
Dependent Claim
84 words
A vapor discharge lamp comprising: an enclosed discharge tube having a pair of main electrodes mounted at spaced apart locations therein, the discharge tube including a fill of at least a metal vapor and a starting gas; a radiation source including radioactively impregnated ceramic material having an outer protection portion comprising a vitrified radioactive material; said radiation source being located within said discharge tube; an outer bulb for enclosing the discharge tube; and a circuit for electrically generating an arc between the main electrodes.
Claim 3
Dependent Claim
18 words
The lamp of claim 1, wherein the radiation source has a half-life of less than 1×10 4 years.
Claim 4
Dependent Claim
18 words
The lamp of claim 2, wherein the radiation source includes a ceramic body having radioactive material dispersed therein.
Claim 5
Dependent Claim
23 words
The lamp of claim 3, wherein the outer protection portion includes a mechanically hard vitreous layer for protecting the radiation source against defacement.
Claim 6
Dependent Claim
150 words
The lamp of claim 3, wherein the radioactive material includes at least one selected from carbon 14 ( 14 C), sodium 22 ( 22 Na), calcium 45 ( 45 Ca), iron 55 ( 55 Fe), cobalt 60 ( 60 CO), nickel 63 ( 63 Ni), zinc 65 ( 65 Zn), manganese 54 ( 54 Mn), strontium 90 ( 90 Sr), ruthenium 106 ( 106 Ru), silver 110 ( 11O Ag), antimony 125 ( 125 Sb), cesium 134 ( 134 Cs), cesium 137 ( 137 Cs), barium 133 ( 133 Ba), cerium 144 ( 144 Ce), promethium 147 ( 147 Pm), europium 154 ( 154 Eu), europium 155 ( 135 Eu), gold 195 (195Au), thallium 204 ( 204 Tl), actinium 227 ( 227 AC), americium 241 ( 241 AM), curium 242 ( 242 Cm), curium 244 ( 244 CM), radium 226 (226Ra), radium 228 (228Ra) and thorium 228 ( 228 Th).
Claim 7
Independent Claim
54 words
The method for making a radiation source for a metal vapor discharge lamp, comprising the steps of: mixing ceramic materials to form a ceramic body; impregnating the cermaic body with radioactive material; and vitrifying at least the outer portion of the ceramic body to yield an outer protection portion comprising a vitrified radioactive material.
Claim 8
Independent Claim
54 words
The method for making a radiation source for a metal vapor discharge lamp, comprising the steps of: mixing ceramic materials to form a ceramic body; impregnating the cermaic body with radioactive material; and vitrifying at least the outer portion of the ceramic body to yield an outer protection portion comprising a vitrified radioactive material.
Claim 9
Dependent Claim
26 words
The method of claim 6 wherein the step of vitrifying includes the step of heating the ceramic body to about 1,300° C. for about 2 hours.
Claim 10
Dependent Claim
27 words
The method of claim 7 wherein the step of heating includes the step of disposing the ceramic body in one of an inert gas and a vacuum.
Claim 11
Dependent Claim
36 words
The method of claim 8 wherein the step of impregnating includes the step of selecting a radioactive material having a half-life of less than 1×10 4 years, and dispersing the radioactive material in the ceramic body.
Claim 12
Independent Claim
47 words
The method for making a radiation source for a metal vapor discharge lamp, comprising the steps of: mixing powders of ceramic material and material; and heating the mixture to about 1,300° C. for about 2 hours to yield an outer protection portion comprising a vitrified radioactive material.
Claim 13
Independent Claim
47 words
The method for making a radiation source for a metal vapor discharge lamp, comprising the steps of: mixing powders of ceramic material and material; and heating the mixture to about 1,300° C. for about 2 hours to yield an outer protection portion comprising a vitrified radioactive material.
Claim 14
Dependent Claim
27 words
The method of claim 10 wherein the step of heating includes the step of disposing the ceramic material in one of an inert gas and a vacuum.
Claim 15
Dependent Claim
28 words
The method of claim 11 wherein the step of heating includes the steps of sintering the mixture and vitrifying at least the outer portion of the sintered mixture.
Claim 16
Dependent Claim
38 words
The lamp of claim 1, wherein the radiation source includes a ceramic body having radioactive material dispersed therein, and the amount of radioactive material is limited so that it emits rays of less than 100 μCi per lamp.
Claim 17
Dependent Claim
25 words
The method of claim 6, wherein the amount of radioactive material is limited so that it emits rays of less than 100 μCi per lamp.
Claim 18
Dependent Claim
25 words
The method of claim 10, wherein the amount of radioactive material is limited so that it emits rays of less than 100 μCi per lamp.
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) | 1992-05-01 | 1992-10-31 | 1993-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-01 | 1996-10-31 | 1997-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-01 | 2000-10-31 | 2001-05-02 | $7700.00 | Window Closed / Lapsed |