US4719387A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Infra-red phosphors and fluorescent lamp containing the same
Assignee: EMI Group Ltd
•
Filing: 1986-11-13
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Granted: 1988-01-12
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Expires: 2006-11-13
Abstract
Abstract An infra-red emissive phosphor consists of chromium activated cerium manganese aluminate having a hexagonal crystal structure and represented by the general formula: ##EQU1## where x is from 0.3 to 3.0, y is from 0.01 to 2.0, z is from 0.001 to 0.3 and R is manganese, in which up to 95 atomic percent of the manganese may be replaced by an equivalent amount of zinc or magnesium or both.
Inventors
- 👤 Colin L. R. Catherall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:08
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7715; C09K11/7721
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
106 words
A phosphor emitting in the region of the electromagnetic spectrum between 650 and 800 nm when excited by 254 nm radiation consisting of chromium activated cerium manganese aluminate having a hexagonal crystal structure and represented by the general formula: ##EQU4## where x is from 0.3 to 3.0, y is from 0.01 to 2.0, z is from 0.001 to 0.3 and R is manganese, in which up to 95 atomic percent of the manganese is replaceable by an equivalent amount of zinc or magnesium or both, said phosphor emitting a greater luminance in said region than the same phosphor absent manganese when excited by 254 nm radiation.
Claim 2
Dependent Claim
106 words
A phosphor emitting in the region of the electromagnetic spectrum between 650 and 800 nm when excited by 254 nm radiation consisting of chromium activated cerium manganese aluminate having a hexagonal crystal structure and represented by the general formula: ##EQU4## where x is from 0.3 to 3.0, y is from 0.01 to 2.0, z is from 0.001 to 0.3 and R is manganese, in which up to 95 atomic percent of the manganese is replaceable by an equivalent amount of zinc or magnesium or both, said phosphor emitting a greater luminance in said region than the same phosphor absent manganese when excited by 254 nm radiation.
Claim 3
Dependent Claim
14 words
A phosphor according to claim 1, in which y is from 0.01 to 1.0.
Claim 4
Dependent Claim
14 words
A phosphor according to claim 2 in which y is between 0.1 and 1.0.
Claim 5
Dependent Claim
14 words
A phosphor according to claim 3 in which y is between 0.1 and 0.6.
Claim 6
Dependent Claim
11 words
A phosphor according to claim 4 in which y is 0.5.
Claim 7
Dependent Claim
14 words
A phosphor according to claim 1 in which z is from 0.001 to 0.2.
Claim 8
Dependent Claim
14 words
A phosphor according to claim 6 in which z is between 0.01 and 0.1.
Claim 9
Dependent Claim
11 words
A phosphor according to claim 7 in which z is 0.02.
Claim 10
Dependent Claim
14 words
A phosphor according to claim 1 in which x is between 0.4 and 1.5.
Claim 11
Dependent Claim
11 words
A phosphor according to claim 9 in which x is 0.77.
Claim 12
Dependent Claim
26 words
A fluorescent lamp comprising an envelope, the internal surface of which is coated with a phosphor according to any one of the claims 1 to 10.
References Cited (Backward Citations)
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JPS49123992A
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US4003845A
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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) | 1991-01-11 | 1991-07-13 | 1992-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-11 | 1995-07-13 | 1996-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-11 | 1999-07-13 | 2000-01-12 | $7700.00 | Window Closed / Lapsed |