US5041758A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low-pressure mercury vapor discharge lamp
Assignee: US Philips Corp
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Filing: 1990-03-30
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Granted: 1991-08-20
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Expires: 2010-03-30
Abstract
Abstract Low-pressure mercury vapor discharge lamp in which the envelope (1) is provided on its inside with a luminescent layer (5), which comprises green luminescing Zn 2 SiO 4 :Mn 2+ (willemite), while between the luminescent layer (5) and the envelope (1) a luminescent intermediate layer (6) is present, which comprises luminescent Sr 4 Al 14 O 24 : Eu 2+ , in which the Sr may be replaced for up to 25 mol. % by Ca.
Inventors
- 👤 Cornelis Huiskes
- 👤 Roelof Brinkman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 00:24
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/59; C09K11/592; C09K11/595; C09K11/77; C09K11/7728; C09K11/7734; H; H01; H01J; H01J61/00; H01J61/02; H01J61/38; H01J61/42; H01J61/48
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
124 words
A low-pressure mercury vapour discharge lamp having an envelope which is sealed in a vacuum-tight manner and transmits radiation, and which contains mercury and a rare gas, said envelope being provided on its inside with a luminescent layer comprising a green luminescing zinc orthosilicate activated by bivalent manganese, defined by the formula Zn 2 SiO 4 :Mn 2+ , characterized in that a luminescent intermediate layer is present on the inside of the envelope at the side of the luminescent layer remote from the discharge, said intermediate layer comprising a luminescent strontium aluminate activated by bivalent europium, defined by the formula Sr 4 Al 14 O 25 :Eu 2+ , in which the Sr may be replaced up to 25 mol. % by Ca.
Claim 2
Dependent Claim
124 words
A low-pressure mercury vapour discharge lamp having an envelope which is sealed in a vacuum-tight manner and transmits radiation, and which contains mercury and a rare gas, said envelope being provided on its inside with a luminescent layer comprising a green luminescing zinc orthosilicate activated by bivalent manganese, defined by the formula Zn 2 SiO 4 :Mn 2+ , characterized in that a luminescent intermediate layer is present on the inside of the envelope at the side of the luminescent layer remote from the discharge, said intermediate layer comprising a luminescent strontium aluminate activated by bivalent europium, defined by the formula Sr 4 Al 14 O 25 :Eu 2+ , in which the Sr may be replaced up to 25 mol. % by Ca.
Claim 3
Dependent Claim
28 words
A low-pressure mercury vapour discharge lamp as claimed in claim 1, characterized in that the luminescent intermediate layer is directly applied on the interior wall of the envelope.
Claim 4
Dependent Claim
27 words
A low-pressure mercury vapour discharge lamp as claimed in claim 1 or 2, characterized in that the luminescent layer is directly applied on the luminescent intermediate layer.
References Cited (Backward Citations)
US4208448A
Cited
EP0094132A1
Cited
US4524300A
Cited
JPS60241637A
Cited
US4705986A
Cited
JPS622444A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-08-19 | 1995-02-18 | 1995-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-19 | 1999-02-18 | 1999-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-19 | 2003-02-18 | 2003-08-20 | $7700.00 | Window Closed / Lapsed |