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US4049992A
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Beryllium-containing europium activated phosphate phosphor, luminescent screen and discharge lamp containing same
Assignee: US Philips Corp
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Filing: 1974-05-22
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Granted: 1977-09-20
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Expires: 1994-05-22
Abstract
Abstract A luminescent beryllium-containing phosphate activated by bivalent europium defined by the formula Me a-x Be b Eu x P 2 O 8 where a + b = 3 and 0.01≦x≦0.25 and b has the value 1 or 2. If b = 2, Me mainly represents one of the alkaline earth metals barium, strontium and calcium. If b = 1, Me mainly represents barium and/or strontium. The luminescent phosphate may be used in mercury vapor discharge lamps and in low-pressure cadmium vapor discharge lamps.
Inventors
- 👤 Judicus Marinus Pieter Jan Verstegen
- 👤 Willebrordus Hubertus Martinus Maria VAN DE Spijker
- 👤 Emiel Petrus Juliaan DE Meester
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:22
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7728; C09K11/7737; C09K11/7738; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31971
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
89 words
A luminescent screen provided with a luminescent beryllium-containing phosphate, wherein the phosphate is activated by bivalent europium and is defined by the formula Me a-x Be b Eu x P 2 O 8 where a + b = 3, 0.01 ≦ x ≦ 0.25, and b has the value of 1 or 2 and in which, if b = 2, Me represents barium and in which, if b = 1, Me represents at least one of the alkaline earth metals selected from the group consisting of barium and strontium.
Claim 2
Dependent Claim
89 words
A luminescent screen provided with a luminescent beryllium-containing phosphate, wherein the phosphate is activated by bivalent europium and is defined by the formula Me a-x Be b Eu x P 2 O 8 where a + b = 3, 0.01 ≦ x ≦ 0.25, and b has the value of 1 or 2 and in which, if b = 2, Me represents barium and in which, if b = 1, Me represents at least one of the alkaline earth metals selected from the group consisting of barium and strontium.
Claim 3
Dependent Claim
16 words
A luminescent screen as claimed in claim 1, characterized in that 0.02 ≦ x ≦ 0.15.
Claim 4
Dependent Claim
18 words
A luminescent screen as claimed in claim 1 characterized in that b 23 2, and Me is barium.
Claim 5
Dependent Claim
15 words
A mercury vapour discharge lamp provided with a luminescent screen as claimed in claim 3.
Claim 6
Dependent Claim
24 words
A luminescent screen as claimed in claim 1, characterized in that b = 1 and at least 75 gram-atomic % of Me is barium.
Claim 7
Dependent Claim
16 words
A low-pressure mercury vapour discharge lamp provided with a luminescent screen as claimed in claim 5.
Claim 8
Dependent Claim
24 words
A luminescent screen as claimed in claim 1, characterized in that b = 1 and at least 75 gram-atomic % of Me is strontium.
Claim 9
Dependent Claim
15 words
A mercury vapour discharge lamp provided with a luminescent screen as claimed in claim 7.
Claim 10
Dependent Claim
16 words
A low-pressure cadmium vapour discharge lamp provided with a luminescent screen as claimed in claim 7.
Claim 11
Dependent Claim
79 words
A luminescent beryllium-containing phosphate activated by bivalent bivalent europium and defined by the formula: Me 2-x Be b Eu x P 2 O 8 in which a + b = 3, 0.01 ≦ x ≦ 0.25 and b has the value 1 or 2, in which, if b = 2, Me is barium and in which, if b = 1, Me is at least one of the alkaline earth metals selected from the group consisting of barium and strontium.
Claim 12
Dependent Claim
79 words
A luminescent beryllium-containing phosphate activated by bivalent bivalent europium and defined by the formula: Me 2-x Be b Eu x P 2 O 8 in which a + b = 3, 0.01 ≦ x ≦ 0.25 and b has the value 1 or 2, in which, if b = 2, Me is barium and in which, if b = 1, Me is at least one of the alkaline earth metals selected from the group consisting of barium and strontium.
Claim 13
Dependent Claim
11 words
The luminescent phosphate of claim 10 wherein 0.02 ≦ x≦ 0.15.
Claim 14
Dependent Claim
14 words
The luminescent phosphate of claim 11 wherein b = 2 and Me is barium.
Claim 15
Dependent Claim
21 words
The luminescent phosphate of claim 11 wherein b = 1 and at least 75 gram atom % of Me is barium.
Claim 16
Dependent Claim
21 words
The luminescent phosphate of claim 11 wherein b = 1 and at least 75 gram atom % of Me is strontium.
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) | 1980-09-19 | 1981-03-21 | 1981-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-19 | 1985-03-21 | 1985-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-19 | 1989-03-21 | 1989-09-20 | $7700.00 | Window Closed / Lapsed |