US4335330A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low-pressure mercury vapor discharge lamp
Assignee: US Philips Corp
•
Filing: 1980-02-12
•
Granted: 1982-06-15
•
Expires: 2000-02-12
Abstract
Abstract Low-pressure mercury vapor discharge lamps provided with a luminescent layer and having a relatively high power consumption. Lamps are loaded by at least 500 W per m 2 surface area of the luminescent layer. In some embodiments the lamps have a nominal length of 60 to 150 cm and consume a nominal power of 0.25 to 0.50 W per cm length of the discharge tube.
Inventors
- 👤 Robert C. Peters
- 👤 Louis E. Vrenken
- 👤 Winston D. Couvbenberg
- 👤 Franciscus A. S. Ligthart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:18
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7728; C09K11/7734; C09K11/66; C09K11/666; C09K11/7737; C09K11/7738; C09K11/7739; C09K11/774; C09K11/7766; C09K11/7774; C09K11/778; C09K11/7783; C09K11/7784; C09K11/7792; H; H01; H01J; H01J61/00; H01J61/02; H01J61/38; H01J61/42; H01J61/44; H01J61/70; H01J61/72
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
180 words
A low-pressure mercury vapour discharge lamp having a vacuum-tight, radiation-transmissive envelope, provided with a luminescent layer and a gas filling comprising mercury and a rare gas wherein mercury radiation at 254 nm is generated, and furthermore provided with means for maintaining a column discharge in the gas filling, the power consumed by the column being at least 500 W per m 2 surface area of the luminescent layer, characterized in that the luminesent layer contains a luminescent material which has the property of having a 254 nm-excitation a luminous flux which, after the material has been subjected for 15 minutes to ultraviolet radiation of a wavelength of mainly 185 and 254 nm and a radiation density between 150 and 500 W/m 2 and a ratio of 185 nm power to 254 nm power between 0.20 and 0.40, is not more than 5% lower than the initial luminous flux of the material also at 254 nm excitation and measured under identical circumstances, and in that the combination of cations in the luminescent material has an electronegativity of not more than 1.4.
Claim 2
Dependent Claim
180 words
A low-pressure mercury vapour discharge lamp having a vacuum-tight, radiation-transmissive envelope, provided with a luminescent layer and a gas filling comprising mercury and a rare gas wherein mercury radiation at 254 nm is generated, and furthermore provided with means for maintaining a column discharge in the gas filling, the power consumed by the column being at least 500 W per m 2 surface area of the luminescent layer, characterized in that the luminesent layer contains a luminescent material which has the property of having a 254 nm-excitation a luminous flux which, after the material has been subjected for 15 minutes to ultraviolet radiation of a wavelength of mainly 185 and 254 nm and a radiation density between 150 and 500 W/m 2 and a ratio of 185 nm power to 254 nm power between 0.20 and 0.40, is not more than 5% lower than the initial luminous flux of the material also at 254 nm excitation and measured under identical circumstances, and in that the combination of cations in the luminescent material has an electronegativity of not more than 1.4.
Claim 3
Dependent Claim
32 words
A low-pressure mercury vapour discharge lamp as claimed in claim 1, wherein an electric field strength of 150 to 1000 V/m is maintained in the column discharge during operation of the lamp.
Claim 4
Dependent Claim
40 words
A low-pressure mercury vapour discharge lamp as claimed in claim 2, wherein the envelope has a tubular shape, whose cross-section perpendicular to the axis of the tube is substantially circular and whose inside diameter is from 3 to 15 mm.
Claim 5
Dependent Claim
54 words
A low-pressure mercury vapour discharge lamp as claimed in claim 1, characterized in that the luminescent material is a red luminescing, trivalent europium-activated rare earth oxide in accordance with the formula Ln 2 O 3 :pEu 3+ , wherein Ln represents at least one of the elements Y, Gd and Lu and wherein 0.01≦p≦0.20.
Claim 6
Dependent Claim
90 words
A low-pressure mercury vapour discharge lamp as claimed in claim 1, characterized in that the luminescent material is an aluminate activated by cerium and terbium and having a hexagonal crystal structure related to the structure of magnetoplumbite, which aluminate satisfies the formula (Ce 1-p-q La p Tb q ) 2 O 3 . xMgO.yAl 2 O 3 , wherein up to 25 mol.% of the Al 2 O 3 may have been replaced by Ga 2 O 3 and/or Sc 2 O 3 and wherein 0≦x≦2 10≦y≦16 0≦p≦0.50 0≦q≦0.60 p+q≦0.90
Claim 7
Dependent Claim
104 words
A low-pressure mercury vapour discharge lamp as claimed in claim 1, characterized in that the luminescent material is an aluminate, activated by bivalent europium, by bivalent europium and bivalent manganese or by trivalent cerium and having a hexagonal crystal structure related to the structure of β-alumina, which aluminate satisfies the formula MeO.xMgO.yAl 2 O 3 :pEuO.qMnO.rCe 2 O 3 , wherein Me represents Ba and/or Sr, wherein up to 25 mol.% of the Al 2 O 3 may have been replaced by Ga 2 O 3 and/or Sc 2 O 3 and wherein 0≦x≦2 5≦y≦8 0.01≦p≦0.50 0≦q≦1.0 0≦r≦0.50, wherein Me is Ba if x=0.
Claim 8
Dependent Claim
59 words
A low-pressure mercury vapour discharge lamp as claimed in claim 1, characterized in that the luminescent layer comprises at least a luminescent material of the group consisting of bivalent europium-activated strontium tetraborate, lead-activated barium disilicate, bivalent europium-activated strontium chlorophosphate with apatite structure, gadolinium metaborate activated by cerium and terbium, and gadolinium borate activated by trivalent bismuth and trivalent europium.
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) | 1985-06-14 | 1985-12-14 | 1986-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-14 | 1989-12-14 | 1990-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-14 | 1993-12-14 | 1994-06-15 | $7700.00 | Window Closed / Lapsed |