US4180477A
Expired / Lapsed
US
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Luminescent materials
Assignee: Johnson Matthey PLC
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Filing: 1978-01-17
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Granted: 1979-12-25
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Expires: 1998-01-17
Abstract
Abstract This invention relates to luminescent materials, frequently known as "Phosphors" and suitable for use in cathode ray tubes where a high brightness display is required, for example, in the cockpit of an aircraft. In particular the luminescent material of the invention comprises a luminescent material comprising an aluminium garnet host material optionally including at least one of the elements scandium and gallium and activated by trivalent terbium and having a composition according to the formula RE 3 Al.sub.(5-(y+z)) Sc y Ga z O 12 :Tb, in which RE is one or more of the elements yttrium, gadolinium, lutetium and bismuth and y and z typically have values in the ranges 0≦y≦2 and 0≦z≦5.
Inventors
- 👤 Roderick G. L. Barnes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:07
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7766; C09K11/7774
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
23 words
A luminescent material having the formula Y 2 .91 Tb 0 .09 Al 5 O 12 (Y 2 O 3 ) 0 .02.
Claim 2
Dependent Claim
23 words
A luminescent material having the formula Y 2 .91 Tb 0 .09 Al 5 O 12 (Y 2 O 3 ) 0 .02.
Claim 3
Dependent Claim
85 words
A luminescent material comprising an aluminum garnet host material activated by trivalent terbium having a composition of the formula: RE.sub.(3-x) Tb.sub.x Al.sub.(5-z) Ga.sub.z O.sub.12 (RE.sub.2 O.sub.3).sub.w in which RE is one or more of the elements yttrium, gadolinium, lutetium and bismuth, z has a value in the range of 0≦z≦5, w has a value in the range of 0.02≦w≦0.05 and x lies between 0.01 and 0.5, said luminescent material having enhanced brightness when compared to the corresponding material without the RE 2 O 3 .
Claim 4
Dependent Claim
85 words
A luminescent material comprising an aluminum garnet host material activated by trivalent terbium having a composition of the formula: RE.sub.(3-x) Tb.sub.x Al.sub.(5-z) Ga.sub.z O.sub.12 (RE.sub.2 O.sub.3).sub.w in which RE is one or more of the elements yttrium, gadolinium, lutetium and bismuth, z has a value in the range of 0≦z≦5, w has a value in the range of 0.02≦w≦0.05 and x lies between 0.01 and 0.5, said luminescent material having enhanced brightness when compared to the corresponding material without the RE 2 O 3 .
References Cited (Backward Citations)
US3717584A
Cited
JPS5097590A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-12-24 | 1983-06-25 | 1983-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-24 | 1987-06-25 | 1987-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-24 | 1991-06-25 | 1991-12-25 | $7700.00 | Window Closed / Lapsed |