US4827187A
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US
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Luminescent barium-hexa-aluminate, luminescent screen provided with such an aluminate and low-pressure mercury vapor discharge lamp provided with such a screen
Assignee: US Philips Corp
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Filing: 1988-04-01
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Granted: 1989-05-02
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Expires: 2008-04-01
Abstract
Abstract Luminescent Eu 2+ activated barium-hexa-aluminate mainly having the crystal structure of β'-alumina and being defined by the formula (x-p)BaO.pEuO.(6-0.67x)Al 2 O 3 in which 0.90≦x≦1.22 and 0.005≦p≦0.25 and in which 1 to 20 mol % of the BaO is replaced by at least one of the oxides CaO and 0.67Li= 2 O, exhibits improved performance as a blue line emitter.
Inventors
- 👤 Johannus G. Verlijsdonk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:32
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7728; C09K11/7734; H; H01; H01J; H01J61/00; H01J61/02; H01J61/38; H01J61/42; H01J61/44
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
54 words
A luminescent Eu 2+ activated barium-hexa-aluminate mainly having the crystal structure of β'-alumina, characterized in that the aluminate is defined by the formula (x-p)BaO.pEuO.(6-0.67x)Al.sub.2 O.sub.3 in which 0.90≦x≦1.22 and 0.005≦p≦0.25 and in which 1 to 20 mol% of the BaO is replaced by at least one of the oxides CaO and 0.67Li 2 O.
Claim 2
Dependent Claim
54 words
A luminescent Eu 2+ activated barium-hexa-aluminate mainly having the crystal structure of β'-alumina, characterized in that the aluminate is defined by the formula (x-p)BaO.pEuO.(6-0.67x)Al.sub.2 O.sub.3 in which 0.90≦x≦1.22 and 0.005≦p≦0.25 and in which 1 to 20 mol% of the BaO is replaced by at least one of the oxides CaO and 0.67Li 2 O.
Claim 3
Dependent Claim
29 words
A luminescent aluminate as claimed in claim 1, in which 1.05≦x≦1.20 and in which 5 to 15 mol% of the BaO is replaced by CaO and/or 0.67Li 2 O.
Claim 4
Dependent Claim
20 words
A luminescent screen having a luminescent layer provided on a support, comprising a luminescent aluminate as claimed in claim 2.
Claim 5
Dependent Claim
17 words
A low pressure mercury vapour discharge lamp provided with a luminescent screen as claimed in claim 3.
Claim 6
Dependent Claim
20 words
A luminescent screen having a luminescent layer provided on a support, comprising a luminescent aluminate as claimed in claim 1.
Claim 7
Dependent Claim
16 words
A low-pressure mercury vapour discharge lamp provided with a luminescent screen as claimed in claim 5.
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 |