US4297584A
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US
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Rare earth phosphors and phosphor screens
Assignee: Lockheed Martin Corp
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Filing: 1977-04-11
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Granted: 1981-10-27
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Expires: 1997-04-11
Abstract
Abstract This invention relates to rare earth phosphor screens for converting image carrying incident radiation to image carrying visible or near-visible radiation and to the rare earth phosphor materials utilized in such screens. The invention further relates to methods for converting image carrying charged particles to image carrying radiation principally in the blue and near-ultraviolet region of the spectrum and to stabilized rare earth phosphors characterized by having a continuous surface layer of the phosphors of the invention. More particularly, the phosphors of the invention are oxychlorides and oxybromides of yttrium, lanthanum and gadolinium activated with trivalent cerium and the conversion screens are of the type illustratively including x-ray conversion screens, image amplifier tube screens, neutron imaging screens, cathode ray tube screens, high energy gamma ray screens, scintillation detector screens and screens for real-time translation of image carrying high energy radiation to image carrying visible or near-visible radiation.
Inventors
- 👤 Robert A. Buchanan
- 👤 T. Grant Maple
- 👤 Alden F. Sklensky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:36
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7701; C09K11/7766; C09K11/7767
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
99 words
A stabilized rare earth oxybromide phosphor consisting essentially of at least one oxybromide selected from the group consisting of yttrium oxybromide, lanthanum oxybromide and gadolinium oxybromide in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by trivalent cerium ions and characterized by having an integral, continuous surface layer of at least one rare earth oxychloride selected from the group consisting of yttrium oxychloride, lanthanum oxychloride and gadolinium oxychloride in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by trivalent cerium ions.
Claim 2
Dependent Claim
99 words
A stabilized rare earth oxybromide phosphor consisting essentially of at least one oxybromide selected from the group consisting of yttrium oxybromide, lanthanum oxybromide and gadolinium oxybromide in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by trivalent cerium ions and characterized by having an integral, continuous surface layer of at least one rare earth oxychloride selected from the group consisting of yttrium oxychloride, lanthanum oxychloride and gadolinium oxychloride in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by trivalent cerium ions.
Claim 3
Dependent Claim
30 words
A rare earth phosphor is accordance with claim 1, wherein from about 0.005 percent to about 5 percent of said host metal ions have been replaced by trivalent cerium ions.
Claim 4
Dependent Claim
22 words
A rare earth phosphor in accordance with claim 1, wherein said oxybromide is yttrium oxybromide and said surface layer is yttrium oxychloride.
Claim 5
Dependent Claim
22 words
A rare earth phosphor in accordance with claim 1, wherein said oxybromide is lanthanum oxybromide and said surface layer is lanthanum oxychloride.
Claim 6
Dependent Claim
22 words
A rare earth phosphor in accordance with claim 1, wherein said oxybromide in gadolinium oxybromide and said surface layer is gadolinium oxychloride.
Claim 7
Dependent Claim
97 words
A stabilized rare earth oxybromide phosphor having the empirical formula: LnOBr:A where Ln is at least one rare earth host metal ion selected from the group consisting of yttrium, lanthanum and gadolinium, A is a luminescent activator and in which from about 0.001 percent to about 10 percent of the trivalent host metal ions have been replaced by said luminescent ions and characterized by having an integral surface layer having the empirical formula: LnOCl:A in which from about 0.001 percent to about 10 percent of the trivalent host metal ions have been replaced by said luminescent ions.
Claim 8
Dependent Claim
97 words
A stabilized rare earth oxybromide phosphor having the empirical formula: LnOBr:A where Ln is at least one rare earth host metal ion selected from the group consisting of yttrium, lanthanum and gadolinium, A is a luminescent activator and in which from about 0.001 percent to about 10 percent of the trivalent host metal ions have been replaced by said luminescent ions and characterized by having an integral surface layer having the empirical formula: LnOCl:A in which from about 0.001 percent to about 10 percent of the trivalent host metal ions have been replaced by said luminescent ions.
Claim 9
Dependent Claim
33 words
A stabilized rare earth oxybromide phosphor in accordance with claim 6, wherein said luminescent ion A is at least one lanthanide ion selected from the group having atomic numbers from 59 through 70.
Claim 10
Dependent Claim
35 words
A stabilized rare earth oxybromide phosphor in accordance with claim 7, wherein from about 0.005 percent to about 5 percent of said host metal ions have been replaced by at least one said lanthanide ion.
Claim 11
Dependent Claim
98 words
A stabilized rare earth phosphor consisting essentially of at least one oxybromide selected from the group consisting of yttrium oxybromide, lanthanum oxybromide and gadolinium oxybromide in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by trivalent cerium ions and characterized by having an integral, continuous surface layer of at least one rare earth oxyfluoride selected from the group consisting of yttrium oxyfluoride, lanthanum oxyfluoride and gadolinium oxyfluoride in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by trivalent cerium ions.
Claim 12
Dependent Claim
98 words
A stabilized rare earth phosphor consisting essentially of at least one oxybromide selected from the group consisting of yttrium oxybromide, lanthanum oxybromide and gadolinium oxybromide in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by trivalent cerium ions and characterized by having an integral, continuous surface layer of at least one rare earth oxyfluoride selected from the group consisting of yttrium oxyfluoride, lanthanum oxyfluoride and gadolinium oxyfluoride in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by trivalent cerium ions.
Claim 13
Dependent Claim
30 words
A rare earth phosphor in accordance with claim 9, wherein from about 0.005 percent to about 5 percent of said host metal ions have been replaced by trivalent cerium ions.
Claim 14
Dependent Claim
97 words
A stabilized rare earth oxybromide phosphor having the empirical formula: LnOBr:A where Ln is at least one rare earth host metal ion selected from the group consisting of yttrium, lanthanum and gadolinium, A is a luminescent activator and in which from about 0.001 percent to about 10 percent of the trivalent host metal ions have been replaced by said luminescent ions and characterized by having an integral surface layer having the empirical formula: LnOF:A in which from about 0.001 percent to about 10 percent of said trivalent host metal ions have been replaced by said luminescent ions.
Claim 15
Dependent Claim
97 words
A stabilized rare earth oxybromide phosphor having the empirical formula: LnOBr:A where Ln is at least one rare earth host metal ion selected from the group consisting of yttrium, lanthanum and gadolinium, A is a luminescent activator and in which from about 0.001 percent to about 10 percent of the trivalent host metal ions have been replaced by said luminescent ions and characterized by having an integral surface layer having the empirical formula: LnOF:A in which from about 0.001 percent to about 10 percent of said trivalent host metal ions have been replaced by said luminescent ions.
Claim 16
Dependent Claim
32 words
A rare earth phosphor in accordance with claim 11, wherein said trivalent luminescent ion A is at least one lanthanide ion selected from the group having atomic numbers from 59 through 70.
Claim 17
Dependent Claim
33 words
A rare earth phosphor in accordance with claim 12, wherein from about 0.005 percent to about 5 percent of said host metal ions have been replaced by at least one said lanthanide ion.
Claim 18
Dependent Claim
130 words
A conversion screen for converting an image carrying energy field into image carrying visible or near-visible energy consisting essentially of a rare earth phosphor and a substrate for said phosphor, said phosphor having the empirical formula: LnOBr:Ce where Ln is at least one rare earth host metal ion selected from the group consisting of yttrium, lanthanum and gadolinium in which from about 0.001 percent to 10 percent of the host metal ions have been replaced by trivalent cerium ions and characterized by having an integral surface layer having the empirical formula: LnOB:Ce where B is at least one oxyhalide selected from the group consisting of chlorine and fluorine and in which from about 0.001 percent to 10 percent of the host metal ions have been replaced by said cerium ions.
Claim 19
Dependent Claim
130 words
A conversion screen for converting an image carrying energy field into image carrying visible or near-visible energy consisting essentially of a rare earth phosphor and a substrate for said phosphor, said phosphor having the empirical formula: LnOBr:Ce where Ln is at least one rare earth host metal ion selected from the group consisting of yttrium, lanthanum and gadolinium in which from about 0.001 percent to 10 percent of the host metal ions have been replaced by trivalent cerium ions and characterized by having an integral surface layer having the empirical formula: LnOB:Ce where B is at least one oxyhalide selected from the group consisting of chlorine and fluorine and in which from about 0.001 percent to 10 percent of the host metal ions have been replaced by said cerium ions.
Claim 20
Dependent Claim
13 words
A conversion screen in accordance with claim 14, wherein said oxyhalide is chlorine.
Claim 21
Dependent Claim
13 words
A conversion screen in accordance with claim 14, wherein said oxyhalide is fluorine.
Claim 22
Dependent Claim
29 words
A conversion screen in accordance with claim 14, wherein from about 0.005 percent to about 5 percent of said host metal ions have been replaced by said cerium ions.
Claim 23
Dependent Claim
139 words
A combination metal and phosphor imaging screen for converting high energy radiation to visible or near-visible radiation, said phosphor having the empirical formula: LnOBr:Ce where Ln is at least one rare earth host metal ion selected from the group consisting of yttrium, lanthanum and gadolinium in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by trivalent cerium ions and said metal being selected from those metals which fall within the group of elements having atomic numbers 46 through 83, and characterized by having an integral surface layer having the empirical formula: LnOB:Ce where B is at least one oxyhalide selected from the group consisting of chlorine and fluorine and in which from about 0.001 percent to 10 percent of the host metal ions have been replaced by said cerium ions.
Claim 24
Dependent Claim
139 words
A combination metal and phosphor imaging screen for converting high energy radiation to visible or near-visible radiation, said phosphor having the empirical formula: LnOBr:Ce where Ln is at least one rare earth host metal ion selected from the group consisting of yttrium, lanthanum and gadolinium in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by trivalent cerium ions and said metal being selected from those metals which fall within the group of elements having atomic numbers 46 through 83, and characterized by having an integral surface layer having the empirical formula: LnOB:Ce where B is at least one oxyhalide selected from the group consisting of chlorine and fluorine and in which from about 0.001 percent to 10 percent of the host metal ions have been replaced by said cerium ions.
Claim 25
Dependent Claim
14 words
A combination metal-phosphor screen in accordance with claim 18, wherein said oxyhalide is chlorine.
Claim 26
Dependent Claim
14 words
A combination metal-phosphor screen in accordance with claim 19 wherein said oxyhalide is fluorine.
Claim 27
Dependent Claim
30 words
A combination metal-phosphor screen in accordance with claim 19, wherein from about 0.005 percent to about 5 percent of said host metal ions have been replaced by said cerium ions.
Claim 28
Dependent Claim
26 words
A combination metal-phosphor screen in accordance with claim 18 wherein said metal is selected from the group consisting of tantalum, tungsten, rhenium, iridium, platinum and lead.
Claim 29
Independent Claim
152 words
A method of translating an image carrying field into radiation principally in the blue and near-ultraviolet region of the spectrum comprising the steps of positioning in said energy field a phosphor and irradiating said phosphor with said energy field, thereby to convert said energy into said blue and near-ultraviolet radiation, said phosphor having the empirical formula: LnOBr:Ce when Ln is at least one rare earth host metal ion selected from the group consisting of yttrium, lanthanum and gadolinium in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by trivalent cerium ions and characterized by having an integral surface layer having the empirical formula: LnOB:Ce where B is at least one oxyhalide selected from the group consisting of chloride and fluorine and in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by said cerium ions.
Claim 30
Independent Claim
152 words
A method of translating an image carrying field into radiation principally in the blue and near-ultraviolet region of the spectrum comprising the steps of positioning in said energy field a phosphor and irradiating said phosphor with said energy field, thereby to convert said energy into said blue and near-ultraviolet radiation, said phosphor having the empirical formula: LnOBr:Ce when Ln is at least one rare earth host metal ion selected from the group consisting of yttrium, lanthanum and gadolinium in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by trivalent cerium ions and characterized by having an integral surface layer having the empirical formula: LnOB:Ce where B is at least one oxyhalide selected from the group consisting of chloride and fluorine and in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by said cerium ions.
Claim 31
Dependent Claim
12 words
A method in accordance with claim 23, wherein said oxyhalide is chlorine.
Claim 32
Dependent Claim
12 words
A method in accordance with claim 23, wherein said oxyhalide is fluorine.
Claim 33
Dependent Claim
28 words
A method in accordance with claim 23, wherein from about 0.005 percent to about 5 percent of said host metal ions have been replaced by said cerium ions.
Claim 34
Independent Claim
179 words
A method of translating an image carrying high energy field into radiation principally in the blue and near-ultraviolet region of the spectrum comprising the steps of positioning in said energy field a combination metal and phosphor imaging screen and irradiating said screen with said high energy field, thereby to convert said energy into said blue and near-ultraviolet radiation, said phosphor having the empirical formula: LnOBr:Ce where Ln is at least one rare earth host metal ion selected from the group consisting of yttrium, lanthanum and gadolinium in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by trivalent cerium ions and said metal is a metal selected from the group consisting of metals having atomic numbers 46 through 83 and characterized by having an integral surface layer having the empirical formula: LnOB:Ce where B is at least one oxyhalide selected from the group consisting of chlorine and fluorine and in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by said cerium ions.
Claim 35
Independent Claim
179 words
A method of translating an image carrying high energy field into radiation principally in the blue and near-ultraviolet region of the spectrum comprising the steps of positioning in said energy field a combination metal and phosphor imaging screen and irradiating said screen with said high energy field, thereby to convert said energy into said blue and near-ultraviolet radiation, said phosphor having the empirical formula: LnOBr:Ce where Ln is at least one rare earth host metal ion selected from the group consisting of yttrium, lanthanum and gadolinium in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by trivalent cerium ions and said metal is a metal selected from the group consisting of metals having atomic numbers 46 through 83 and characterized by having an integral surface layer having the empirical formula: LnOB:Ce where B is at least one oxyhalide selected from the group consisting of chlorine and fluorine and in which from about 0.001 percent to about 10 percent of the host metal ions have been replaced by said cerium ions.
Claim 36
Dependent Claim
12 words
A method in accordance with claim 27, wherein said oxyhalide is chlorine.
Claim 37
Dependent Claim
12 words
A method in accordance with claim 27, wherein said oxyhalide is fluorine.
Claim 38
Dependent Claim
28 words
A method in accordance with claim 29, wherein from about 0.005 percent to about 5 percent of the host metal ions have been replaced by said cerium ions.
Claim 39
Dependent Claim
34 words
A method in accordance with claim 27, wherein said blue and near-ultraviolet radiation is detected and converted into a video signal by a TV camera and said signal is displayed on a TV monitor.
Claim 40
Dependent Claim
17 words
A method in accordance with claim 31, wherein said video signal is processed by a computer system.
Claim 41
Dependent Claim
24 words
A method in accordance with claim 27 wherein said metal is selected from the group consisting of tantalum, tungsten, rhenium, iridium, platinum and lead.
References Cited (Backward Citations)
GB492722A
Cited
GB607910A
Cited
US3591516A
Cited
US3617743A
Cited
US3829700A
Cited
US3872309A
Cited
US3891852A
Cited
US4054798A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-26 | 1985-04-27 | 1985-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-26 | 1989-04-27 | 1989-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-26 | 1993-04-27 | 1993-10-27 | $7700.00 | Window Closed / Lapsed |