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US4233538A
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Luminescent lead-activated alkaline earth metal rare earth metal borates and mercury vapor discharge lamp containing the same
Assignee: US Philips Corp
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Filing: 1979-04-18
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Granted: 1980-11-11
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Expires: 1999-04-18
Abstract
Abstract Luminescent lead-activated alkaline earth metal rare earth metal borates having compositions defined by the formula Me1-pPbpLa1-x-yYxGdyBO4, where Me represents strontium and/or calcium, where 0.005 </=p</=0.30 and 0</=x</=0.1, and where O</=y</=0.5 when at least 75 mole% of Me is Ca and O</=y</=0.1 when less than 75 mole% of Me is Ca. The borate may be used in the luminescent screen of low-pressure mercury vapor discharge lamps.
Inventors
- 👤 Willebrordus H. M. M. VAN DE Spijker
- 👤 Willem L. Konijnendijk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:06
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7766; C09K11/778
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
69 words
A luminescent lead-activated alkaline earth metal rare earth metal borate having a hexagonal crystal structure and a composition defined by the formula Me.sub.1-p Pb.sub.p La.sub.1-x-y Y.sub.x Gd.sub.y BO.sub.4, wherein Me represents strontium and/or calcium, where 0.005≦p≦0.30 and 0≦x≦0.1, and wherein 0≦y≦0.5 when at least 75 mole% of Me is Ca and 0≦y≦0.1 when less than 75 mole% of Me is Ca and exhibiting an emission maximum of 465-470 nm.
Claim 2
Dependent Claim
69 words
A luminescent lead-activated alkaline earth metal rare earth metal borate having a hexagonal crystal structure and a composition defined by the formula Me.sub.1-p Pb.sub.p La.sub.1-x-y Y.sub.x Gd.sub.y BO.sub.4, wherein Me represents strontium and/or calcium, where 0.005≦p≦0.30 and 0≦x≦0.1, and wherein 0≦y≦0.5 when at least 75 mole% of Me is Ca and 0≦y≦0.1 when less than 75 mole% of Me is Ca and exhibiting an emission maximum of 465-470 nm.
Claim 3
Dependent Claim
23 words
A luminescent lead-activated alkaline earth metal rare earth metal borate as claimed in claim 1, characterized in that Me is Sr and x=y=0.
Claim 4
Dependent Claim
25 words
A luminescent lead-activated alkaline earth metal rare earth metal borate of claim 1 of the formula Sr 0 .95 Pb 0 .05 LaBO 4 .
Claim 5
Dependent Claim
22 words
A luminescent lead-activated alkaline earth metal rare earth metal borate of claim 1 of the formula Ca 0 .95 Pb0.05LaBO 4 .
Claim 6
Dependent Claim
31 words
A luminescent lead-activated alkaline earth metal rare earth metal borate of claim 1 of the formula Sr 0 .95 Pb 0 .05 La 0 .9 Gd 0 .1 BO 4 .
Claim 7
Dependent Claim
31 words
A luminescent lead-activated alkaline earth metal rare earth metal borate of claim 1 of the formula Sr 0 .95 Pb 0 .05 La 0 .9 Y 0 .1 BO 4 .
Claim 8
Dependent Claim
17 words
A luminescent lead-activated alkaline earth metal rare earth metal borate of claim 1 wherein p is 0.08.
Claim 9
Dependent Claim
17 words
A luminescent lead-activated alkaline earth metal rare earth metal borate of claim 1 wherein p is 0.20.
Claim 10
Dependent Claim
17 words
A luminescent lead-activated alkaline earth metal rare earth metal borate of claim 1 wherein p is 0.03.
Claim 11
Dependent Claim
20 words
A low-pressure mercury vapor discharge lamp containing the luminescent lead-activated alkaline earth metal rare earth metal borate of claim 1.
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) | 1983-11-11 | 1984-05-12 | 1984-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-11 | 1988-05-12 | 1988-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-11 | 1992-05-12 | 1992-11-11 | $7700.00 | Window Closed / Lapsed |