Patent US5825125A successfully refreshed from Google Patents.
US5825125A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Neon discharge lamp
Assignee: US Philips Corp
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Filing: 1996-01-26
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Granted: 1998-10-20
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Expires: 2016-01-26
Abstract
Abstract A lighting unit includes a discharge vessel having a wall provided with a first luminescent layer, a gas fill consisting essentially of neon at a pressure less than 30 mbar, and a means for providing a constant DC current for exciting the fill in the discharge vessel to emit UV light for exciting the luminescent layer. DC operation offers substantially higher luminous flux over AC operation. The lighting unit may further include a housing having a reflective surface, a second luminescent layer, and a filter incorporated within the discharge vessel.
Inventors
- 👤 Franciscus A. S. Ligthart
- 👤 Rolf E. de Man
- 👤 Christianus J. Roozekrans
- 👤 Dick Van Der Voort
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:09
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/38; H01J61/42; H01J61/44; H01J61/48
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
69 words
A lighting unit comprising a discharge vessel having a wall provided with a luminescent screen comprising a first luminescent layer, a gas filling in said discharge vessel, said gas filling consisting essentially of neon having a pressure less than 30 mbar at ambient temperature, and means for providing a constant DC current for exciting said filling in said discharge vessel to emit ultraviolet light which excites the luminescent layer.
Claim 2
Dependent Claim
69 words
A lighting unit comprising a discharge vessel having a wall provided with a luminescent screen comprising a first luminescent layer, a gas filling in said discharge vessel, said gas filling consisting essentially of neon having a pressure less than 30 mbar at ambient temperature, and means for providing a constant DC current for exciting said filling in said discharge vessel to emit ultraviolet light which excites the luminescent layer.
Claim 3
Dependent Claim
17 words
A lighting unit as claimed in claim 1, wherein the first luminescent layer comprises a green-luminescing substance.
Claim 4
Dependent Claim
20 words
A lighting unit as claimed in claim 2, wherein the first luminescent layer comprises zinc silicate activated by bivalent manganese.
Claim 5
Dependent Claim
23 words
A lighting unit as claimed in claim 2, wherein the first luminescent layer comprises the green-luminescing substance yttrium-aluminium garnet activated by trivalent cerium.
Claim 6
Dependent Claim
33 words
A lighting unit as claimed in claim 4, wherein the green-luminescing substance yttrium-aluminium garnet activated by trivalent cerium is of general formula Y 3-x Al 5 O 12 :xCe 3+ , wherein 0.01≦x≦0.20.
Claim 7
Dependent Claim
27 words
A lighting unit as claimed in claim 5, wherein part of the aluminium in the yttrium-aluminium garnet activated by trivalent cerium is replaced by gallium and/or scandium.
Claim 8
Dependent Claim
23 words
A lighting unit as claimed in claim 2, wherein the first luminescent layer comprises the green-luminescing substance yttrium silicate activated by trivalent terbium.
Claim 9
Dependent Claim
15 words
A lighting unit as claimed in claim 7, wherein the discharge lamp incorporates a filter.
Claim 10
Dependent Claim
44 words
A lighting unit as claimed in claim 7, wherein the luminescent screen comprises a second luminescent layer present between the first luminescent layer and the wall of the discharge vessel, said second luminescent layer comprising the green-luminescing substance yttrium-aluminium garnet activated by trivalent cerium.
Claim 11
Dependent Claim
27 words
A lighting unit as claimed in claim 9, wherein part of the aluminium in the yttrium-aluminium garnet activated by trivalent cerium is replaced by gallium and/or scandium.
Claim 12
Dependent Claim
17 words
A lighting unit as claimed in claim 2, wherein the first luminescent layer comprises a blue-luminescing substance.
Claim 13
Dependent Claim
43 words
A lighting unit as claimed in claim 11, wherein the blue-luminescing substance comprises one or more of the luminescent materials belonging to the group formed by MgWO 4 , Y 2-x O 2 S:xTb 3+ and Y 2-x SiO 5 :xCe 3+ .
Claim 14
Dependent Claim
20 words
A lighting unit as claimed in claim 1, wherein the diameter of the discharge vessel is smaller than 5 mm.
Claim 15
Dependent Claim
23 words
A light unit as in claim 1 further comprising a housing having a reflective surface, said discharge vessel being positioned in said housing.
Claim 16
Dependent Claim
15 words
A lighting unit as in claim 1 wherein said pressure is less than 25 mbar.
Claim 17
Dependent Claim
75 words
Method for operating a discharge lamp comprising providing a discharge lamp comprising a discharge vessel having a wall provided with a luminescent screen comprising a first luminescent layer, providing said vessel with a gas filling consisting essentially of neon having a pressure less than 30 mbar at ambient temperature, and exciting said gas filling with a DC-current of substantially constant amplitude, thereby causing the filling to emit enough ultraviolet light to excite the luminescent layer.
Claim 18
Dependent Claim
75 words
Method for operating a discharge lamp comprising providing a discharge lamp comprising a discharge vessel having a wall provided with a luminescent screen comprising a first luminescent layer, providing said vessel with a gas filling consisting essentially of neon having a pressure less than 30 mbar at ambient temperature, and exciting said gas filling with a DC-current of substantially constant amplitude, thereby causing the filling to emit enough ultraviolet light to excite the luminescent layer.
Claim 19
Dependent Claim
17 words
Method as in claim 16 wherein said gas filling has a pressure of less than 25 mbar.
Claim 20
Dependent Claim
13 words
Method as in claim 16 wherein said DC-current is 20 mA or less.
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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) | 2001-10-19 | 2002-04-20 | 2002-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-19 | 2006-04-20 | 2006-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-19 | 2010-04-20 | 2010-10-20 | $7700.00 | Window Closed / Lapsed |