EP0607061B1 - Lampe à décharge de grande intensité - Google Patents

Lampe à décharge de grande intensité Download PDF

Info

Publication number
EP0607061B1
EP0607061B1 EP94300312A EP94300312A EP0607061B1 EP 0607061 B1 EP0607061 B1 EP 0607061B1 EP 94300312 A EP94300312 A EP 94300312A EP 94300312 A EP94300312 A EP 94300312A EP 0607061 B1 EP0607061 B1 EP 0607061B1
Authority
EP
European Patent Office
Prior art keywords
lamp
phosphor
phosphor particles
arc tube
envelope
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP94300312A
Other languages
German (de)
English (en)
Other versions
EP0607061A1 (fr
Inventor
Gary A. Sigai
Vincent C. Bucklen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Flowil International Lighting Holding BV
Original Assignee
Flowil International Lighting Holding BV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Flowil International Lighting Holding BV filed Critical Flowil International Lighting Holding BV
Publication of EP0607061A1 publication Critical patent/EP0607061A1/fr
Application granted granted Critical
Publication of EP0607061B1 publication Critical patent/EP0607061B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/38—Devices for influencing the colour or wavelength of the light
    • H01J61/42—Devices for influencing the colour or wavelength of the light by transforming the wavelength of the light by luminescence
    • H01J61/44—Devices characterised by the luminescent material

Definitions

  • This invention relates to high intensity discharge lamp. More particularly this invention relates to such lamps having a coating of phosphor on the interior surface of an outer envelope.
  • a High Pressure Mercury Vapour (HPMV) lamp known as the Safeline R (Sylvania Trademark) lamp family employs a safety filament to provide a self-extinguishing feature.
  • a leakage of oxidizing atmospheric gases into the outer jacket causes a safety fuse filament within the arc tube circuit to oxidize, open the circuit, and, thus, extinguishing the bulb.
  • a getter is incorporated into the components contained within the outer jacket to provide the required reducing atmosphere to prevent oxidation of this filament.
  • the lamp produces a narrow, elongated column of radiation in a 266 kPa (2000 torr) Hg vapour discharge contained in a quartz arc tube which is, in turn, contained in a outer glass jacket.
  • the central part of the arc tube typically reaches temperatures of 700-800°C.
  • the outer bulb is filled with nitrogen to protect the arc tube and related metal parts from damage and atmospheric corrosion. It also regulates the arc tube operating temperature and acts as a filter to absorb ultraviolet radiation.
  • the outer jacket becomes hot when the lamp is operating, reaching a temperature in excess of 350°C depending on fixture design and lamp wattage.
  • the visible radiation from the HPMV lamp consists almost entirely of the line spectrum from mercury vapour having intense lines at 405, 436, 541, and 578 nanometers and as such can be used as a stand-alone light source. This is in contrast with the low-pressure mercury fluorescent lamp whose emission is from predominantly visible-emitting phosphors used to convert the invisible ultraviolet energy to light emission.
  • Alumina-coated phosphors have been used to improve the maintenance (i.e., the drop off of light output with time) of low-pressure fluorescent lamps where the phosphor is in direct contact with the mercury plasma discharge, eg. US-A-4,710,674 discloses an alumina coating within a conventional fluorescent lamp. The phosphor particles are deposited onto the glass and then an alumina coating is deposited onto the phosphor layer using an electron beam source. Since this type of deposition is line-of-sight, it can be expected that at best even the top particles of the layer are only partially covered.
  • the present invention provides a high intensity discharge lamp comprising an arc tube disposed within an outer sealed glass envelope, said arc tube containing a fill material for supporting an electrical discharge and said envelope having a coating of phosphor particles on the inner surface thereof characterised in that the individual phosphor particles each have a substantially continuous coating of alumina.
  • a high intensity discharge lamp comprising an outer sealed glass envelope having a phosphor coating on an interior surface and in which a pair of electrical conductors extend into the interior of the glass envelope and are electrically connected to a pair of spaced electrodes within an arc tube which contains a chemical fill.
  • an oxidizable electrically conductive element is present in the gaseous atmosphere for interrupting the electrical connection with the arc tube when exposed to air upon breakage of said outer envelope.
  • the outer sealed glass envelope contains a gas and a getter material for removing oxygen from the gas and the phosphor coating comprises alumina coated phosphor particles.
  • a preferred self-extinguishing high intensity discharge light source employs an alumina-coated europium-activated yttrium vanadate phosphor particle as coating on the interior of the outer envelope.
  • the self-extinguishing feature is provided by a safety filament in the reducing atmosphere of the outer envelope.
  • the lamp utilizing an alumina coated yttrium vanadate phosphor of a large particle size has a higher initial brightness, as measured after 100 hours of lamp burning, than a comparable lamp which employs the conventional uncoated smaller sized phosphor.
  • FIG. 1 shows a cross-sectional elevation of a high intensity discharge lamp showing an exploded view of a particle of phosphor coating.
  • the lamp 10 includes a discharge tube or arc tube 11 disposed within an outer glass envelope 13.
  • the outer envelope 13 is sealed to an affixed glass stem member 15 which has an external base member 17.
  • the outer envelope 13 contains a non-oxidizing inert gas, preferably nitrogen.
  • a getter 37 is desirably present to remove oxygen from the atmosphere so as to maintain its reducing characteristics.
  • a coated phosphor particle 3 comprises a phosphor particle 5 with a continuous conformal coating 7 of alumina on the exterior surface.
  • the coated phosphor particles 3 which form a coating on the interior surface of the outer envelope 13 are exposed to the reducing atmosphere of the outer envelope 13.
  • the phosphor is selected so as to convert some of the ultraviolet emitted energy into visible light predominantly in the red region of the spectrum.
  • a preferred phosphor is a europium-activated yttrium vanadate (YVO 4 :Eu) phosphor.
  • a preferred particle size for the phosphor is a Fisher Sub-Sieve Size of from about 7 to about 8.
  • the arc tube 11 has a pair of electrodes 21 and 23 at respective ends which project into the interior of the arc tube 11 to energize a chemical fill for emitting radiation. A portion of emitted ultraviolet portion is absorbed by the inert atmosphere present in the outer jacket while another portion is converted to visible light by the coating of coated phosphor particles 3.
  • Arc tube 11 is generally made of quartz although other types of material may be used such as alumina, yttria or silica.
  • Each electrode 21 and 23 of the arc tube 11 comprises a core portion surrounded by molybdenum or tungsten wire helixes and is connected to respective metal foils 25 and 27, preferably formed of molybdenum which are sealed in the ends of the arc tube 11, preferably by pinch sealing.
  • An electrically conductive oxidizable element 33 which is present in the atmosphere of the outer envelope 13 is electrically connected in series with the arc tube 11.
  • the element or filament 33 is sufficiently oxidizable to a nonconductive state so that the electrical path with the arc tube 11 is interrupted upon contact with air. This can occur upon breakage of the outer envelope 3.
  • the reducing atmosphere present in the outer envelope 13 helps to maintain the integrity of the element 33.
  • the electrical connection of the arc tube 11 with the external source of electricity through the oxidizable element 33 is described in more detail as follows.
  • the oxidizable element 33 is preferably formed from a tungsten coil.
  • a pair of electrical conductors 18 and 19 are sealed into and pass through the stem member 15.
  • Electrical conductors 29 and 31 which are electrically connected to respective foils, 25 and 27, extend outwardly of the respective press seals of the arc tube 11.
  • Conductors 29 and 31 are in turn connected to the respective conductors 19 and 18 projecting from the glass stem member 15.
  • the connection between conductor 29 and conductor 19 is through frame member 35 and the electrically conductive oxidizable element 33.
  • the oxidizable element or filament 33 is constructed of a material that will burn through in the event the outer envelope breaks and admits air, for example tungsten.
  • Getter material 37 is mounted to the frame member 35 to maintain a reducing atmosphere to preserve the electrical conductive nature of the oxidizable element 33 during normal lamp operation.
  • the arc tube 11 is supported by a frame generally indicated at 39.
  • the frame 39 is secured to the glass stem member 15,
  • the frame 39 includes a envelope attachment generally indicated at 41.
  • the frame 39 extends substantially parallel to the longitudinal axis of the lamp.
  • the envelope attachment 41 mates with a dimpled upper partition of the envelope 13 so as to maintain the attached arc tube 11 proper alignment and resist deformation caused by external shock.
  • the drawing illustrates a mogul type base 43, e.g., such as an E27 screw base but it is contemplated that the lamp may have other forms of base such as a bayonet fitting or even a double-ended configuration with a recessed single-contact base.
  • a mogul type base 43 e.g., such as an E27 screw base
  • the lamp may have other forms of base such as a bayonet fitting or even a double-ended configuration with a recessed single-contact base.
  • the lamp may include other structural features commonly found in high intensity lamps such as an auxiliary starting probe or electrode, generally made of tantalum or tungsten which may be provided at the base end of the arc tube adjacent the main electrode 21.
  • an auxiliary starting probe or electrode generally made of tantalum or tungsten which may be provided at the base end of the arc tube adjacent the main electrode 21.
  • the discharge tube 11 contains a chemical fill of inert starting gas and mercury when the lamp is a mercury vapour lamp.
  • Other high intensity discharge lamps may contain, additional ingredients such as alkali metal iodides, and scandium iodide.
  • mercury is dispensed into the unsealed arc tube 11 as an amalgam containing mercury prior to introduction of the starting gas.
  • a charge of mercury is present-in a sufficient amount so when fully vapourized an arc may be sustained.
  • Such an amount should provide an operating mercury-vapour pressure of about 266 kPa (2000 torr) as calculated on the basis of an average gas temperature of about 2000K.
  • Sylvania has developed a series of mercury and Metalarc lamps known as "Safeline R" type.
  • Safeline R In a conventional mercury lamp if the outer glass bulb leaks and ruptures, there is a possibility the arc tube will continue to burn, emitting unshielded ultraviolet radiation. During normal operation, the outer jacket is designed to filter out this harmful radiation.
  • the design of the Safeline R lamp is such that if there is leakage of oxidizing atmospheric gases into the outer jacket, a safety fuse filament within the arc tube circuit will oxidize, opening the circuit, and thus extinguishing the bulb.
  • a getter is incorporated into the components contained within the outer jacket.
  • this getter is an ST101 getter of zirconiumaluminum alloy developed and marketed by SAES Getters, Hamburg, N.Y. This getter provides the required reducing atmosphere to prevent oxidation of this filament.
  • ST101 getter is provided in a handbook entitled Getters for Lamps by E. Rabusin, prepared by SAES Getters. Milan, Italy, p.18-21.
  • FIG. 1 An illustration of a specific Safeline R mount assembly which uses an oxidizable element or safety fuse 33 and a ST101 getter 37 in the form of a strip is shown in FIG. 1.
  • Other lamps set forth in Table 1 are in the Safeline R family of lamps.
  • Safeline R mercury vapour lamps with improved initial brightness are made by the use of an alumina coated yttrium vanadate phosphor (YVO 4 :Eu) as the coating on the outer glass jacket of the HPMV lamp.
  • the initial brightness is further improved by the use of a larger particle sized coated phosphor than the particle size of the uncoated phosphor which is currently used for this application.
  • initial brightness refers to the brightness of the lamp measured after 100 hours of lamp operation. This point in the burning lifetime curve is the industry standard reference point and is selected because at shorter burn time, wide unreliable variations in measured light output occur in HID lamps. This can be attributed to the presence of impurities, incomplete volatilization of condensable components in the lamp, and a variety of other factors.
  • Safeline R Lamps i.e. safety fuse and ST10l Getter.
  • Mercury Lamp Rating Outer Glass Jacket 100 Watt R-40 175 Watt BT28 250 Watt BT2S 400 Watt BT37 1000 Watt BT56 Metalarc R 400 Watt B37 1000 Watt BT56
  • Europium-activated yttrium vanadate phosphor was obtained from the Chemical and Metallurgical Division of GTE, Towanda, PA.
  • the particle physical properties of this powder is given in Table II along with the specification for the Type 2391 phosphor which is conventionally used in HPMV lamps.
  • Particle Size Characterization of YVO 4 Eu Phosphors Phosphor Particle Size Distribution Fisher Sub-Sieve Size Type 25% 50% 75% 2391 2 3 4 2-3 (standard size) 2390 6 8 10 7-8 (large size) * Particle size distributions are based on Coulter counter analysis using ultrasonic dispersion techniques. Sizes listed are in micrometers at listed percentages.
  • a fluid bed column comprising an 80 millimeter ID quartz tube having a quartz frit fused to the bottom acting as a distributor plate.
  • a 65 millimeter stainless agitator disc was positioned inside the quartz tube. The agitator disc was attached to a vibromixer agitator. Approximately 50 millimeters from the base of the agitator a two-micron stainless steel filter element was welded in line and functioned as the diffuser of the oxygen mixture.
  • the agitator disc itself was located approximately 25 millimeters above the quartz distributor.
  • the fluidization column was placed inside a three-zone Lindberg furnace with furnace zone lengths of 158 mm (6 inches), 316 mm (12 inches), and 158 mm (6 inches), respectively.
  • the fluid bed temperature located at the mid-bed height of the column located between the distributor plate and the top of the expanded bed was maintained at approximately 420°C by adjusting the top two furnace zones.
  • Typical zone temperatures as measured by spike thermocouples penetrating through the furnace elements to the outside of the quartz tube were between 460-470°C with the bottom zone turned off.
  • a fluidized bed is formed by passing nitrogen through the distributor plate at the bottom of the quartz column and up through the phosphor particles.
  • the nitrogen gas functions as a carrier gas for the vapourized trimethyl distributor: first, a nitrogen flow of 2 liters per minute is passed through the bubbler containing liquid trimethyl aluminum at approximately 30°C thus vapourizing trimethyl aluminum into the gas flow, second, a flow of 1 litre per minute of nitrogen gas acts as the carrier for the first flow.
  • An alumina coating is formed on the surface of the individual phosphor particles when the vapourized trimethyl aluminum is exposed to oxygen in the bed. The oxygen is introduced through the two-micron filter element located on the shaft of the vibrating mixer above the vibrating disc at a flow of 2.5 litres per minute.
  • XPS X-ray Photoelectron Spectroscopy
  • 175-Watt/DX lamps containing the ST101 getter were fabricated at the HID lamp plant, Manchester, N.H.. using the various europium-doped yttrium vanadate phosphors to be described below.
  • the phosphor was mixed with 5 weight % Aluminum Oxide C.
  • the outer jacket to be coated is supported and rotated during the coating process.
  • Burner manifolds shaped to the configuration of the glass envelopes flank the bulbs as they rotate on a turntable. Gas burners are used to preheat the glass envelopes and make them conductive.
  • SPS X-Ray Photoelectron Spectroscopic
  • the charging mechanism is a corona, produced by applying a high negative potential to four tungsten wires which protrude into the annular path of the two-phase flow of powder and carrier gas.
  • the carrier gas is nitrogen.
  • a diffusing non-conducting nozzle attached to a central plastic rod located in the annulus controls the angular distribution of the exiting charged powder stream.
  • the phosphor thus charged is attracted to the glass envelope due to the electric field between the charging electrode and the grounding brush, forming the adherent electrostatic coating.
  • the powder which is not deposited on the glass makes its way out through to an exhaust.
  • Three sets of lamps were fabricated each containing a different phosphor material. They were the uncoated standard size yttrium vanadate (Type 2391) the phosphor typically used in production, uncoated large-particle size yttrium vanadate (Type 2390), and alumina-coated large-particle size yttrium vanadate.
  • Lifetest data were accumulated for the three sets concurrently from 100 hours through 1000 hours of lamp operation. Brightness levels were not recorded before 100 hours because wide variations in light output are normally observed at shorter time in HID lamps. This is generally attributed to instabilities in the arc due to impurities, incomplete volatilization of condensable components in the lamp, and a variety of other factors.
  • the recorded lifetest data are listed in Table IV. Also tabulated are the percent gains in brightness achieved between the lamps which employ standard yttrium vanadate, the uncoated large particle size yttrium vanadate, and the large size alumina-coated yttrium vanadate as the outer jacket luminescent coating.
  • the data show that after 100 hours of burning, the lamp containing the uncoated large-particle yttrium vanadate achieves a 7% gain over the lamp containing the standard yttrium vanadate. Further, the lamp containing the large-particle alumina coated yttrium vanadate has a brightness gain of almost 11% over the standard size phosphor lamp.
  • the lamp containing the large size alumina-coated yttrium vanadate still maintains its performance gain over the lamp containing the standard uncoated phosphor.
  • the lamp containing uncoated large-particle yttrium vanadate loses its brightness gain so that its brightness is only 5% over the aged lamp containing the standard uncoated phosphor.
  • lamps made from Al 2 O 3 -coated large particle size YVO 4 :Eu phosphor give superior initial brightness to uncoated small- and large-particle size phosphor in a reducing atmosphere.
  • lamps which use the Al 2 O 3 -coated phosphor as a coating on the outer glass jacket achieve a 10 percent brightness advantage in initial brightness over the standard lamp which contains the conventional particle size uncoated YVO 4 :Eu phosphor on the outer jacket.
  • HID lamp types of similar construction to the HPMV/Metalarc R family products line which use the YVO 4 :Eu phosphor for colour correction and which should offer enhanced brightness performance.
  • preferred embodiments of the present invention may be used to enhance the brightness performance of HID lamps that do not use an oxidizable element and could even be applied to lamps of an electrodeless design.
  • the phosphors comply with the following unique requirements, different to those for conventional fluorescent lamps, which are needed for full utilization of the potential value of phosphors in a HPMV lamp, namely
  • a preferred embodiment of the present invention may provide improved brightness and maintenance for a high intensity discharge lamp of the type having a reducing atmosphere in the outer envelope.

Landscapes

  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Discharge Lamp (AREA)

Claims (10)

  1. Lampe à décharge à haute intensité comprenant un tube à arc (11) logé à l'intérieur d'une ampoule extérieure scellée de verre (13), le dit tube à arc enfermant un matériau de remplissage pour favoriser une décharge électrique et la dite ampoule ayant un revêtement de particules (3) de luminophore sur sa paroi interne, caractérisée en ce que les particules individuelles (5) de luminophore ont chacune un revêtement substantiellement continu d'alumine (7).
  2. Lampe selon la revendication 1, caractérisée en ce que les dites particules (3) de luminophore sont choisies pour convertir une énergie émise en ultraviolet à partir du dit tube à arc en une lumière visible de façon prédominante dans la région du rouge du spectre.
  3. Lampe selon la revendication 2, caractérisée en ce que les dites particules (3) de luminophore comprennent un luminophore de vanadate d'yttrium dopé à l'europium.
  4. Lampe selon la revendication 1, 2 ou 3, caractérisée en ce que les dites particules (3) de luminophore présentent une taille sous tamis Fisher comprise entre environ 7 et environ 8.
  5. Lampe selon l'une quelconque des revendications précédentes, caractérisée en ce que le dit tube à arc (11) enferme un matériau de remplissage comprenant du mercure et un gaz inerte.
  6. Lampe selon l'une quelconque des revendications précédentes, caractérisée en ce que la dite ampoule (13) contient une atmosphère gazeuse non oxydante ou réductrice et inclut un élément (37) d'un matériau adapté pour enlever l'oxygène de la dite atmosphère.
  7. Lampe selon la revendication 6, caractérisée en ce que le dit élément (37) du matériau comprend un alliage de zirconium et d'aluminium.
  8. Lampe selon l'une quelconque des revendications précédentes, caractérisée en ce qu'un élément oxydable (37) est disposé à l'intérieur de la dite ampoule (13).
  9. Lampe selon la revendication 8, caractérisée en ce que le dit élément oxydable (37) est prévu pour déconnecter l'alimentation en puissance du dit tube à arc (11) en présence d'oxygène.
  10. Procédé de fabrication d'une lampe à décharge à haute intensité selon l'une quelconque des revendications précédentes, caractérisé en ce que les dites particules individuelles de luminophore (5) sont revêtues par un procédé comprenant les étapes suivantes :
    fluidification d'un lit de particules de luminophore avec de l'azote ;
    chauffage du lit fluidisé jusqu'à environ 420 °C ; et
    introduction d'une dose d'oxygène et d'une dose d'alumium triméthyl vaporisé portée dans un courant d'azote,
    de manière à former un revêtement substantiellement continu d'alumine sur les particules individuelles (5) de luminophore.
EP94300312A 1993-01-15 1994-01-17 Lampe à décharge de grande intensité Expired - Lifetime EP0607061B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US610393A 1993-01-15 1993-01-15
US6103 2001-12-06

Publications (2)

Publication Number Publication Date
EP0607061A1 EP0607061A1 (fr) 1994-07-20
EP0607061B1 true EP0607061B1 (fr) 1998-04-01

Family

ID=21719319

Family Applications (1)

Application Number Title Priority Date Filing Date
EP94300312A Expired - Lifetime EP0607061B1 (fr) 1993-01-15 1994-01-17 Lampe à décharge de grande intensité

Country Status (3)

Country Link
EP (1) EP0607061B1 (fr)
CA (1) CA2113470A1 (fr)
DE (1) DE69409265T2 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013103952A2 (fr) * 2012-01-06 2013-07-11 Advanced Lighting Technologies, Inc. Lampe optique intégrée

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102004021231B4 (de) * 2004-04-30 2012-12-06 Osram Opto Semiconductors Gmbh Verfahren zum Abscheiden eines Lumineszenzkonversionsmaterials

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4585673A (en) * 1984-05-07 1986-04-29 Gte Laboratories Incorporated Method for coating phosphor particles
WO1991010715A1 (fr) * 1990-01-22 1991-07-25 Gte Laboratories Incorporated Phosphores presentant une amelioration du flux lumineux et lampes realisees a partir de ceux-ci

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4241276A (en) * 1979-06-20 1980-12-23 Gte Products Corporation Warm color arc discharge lamp having improved efficiency
US4629939A (en) * 1984-12-21 1986-12-16 North American Philips Lighting Corporation Discharge lamp with automatic shut off
US4979893A (en) * 1988-02-29 1990-12-25 Gte Laboratories Incorporated Method of coating yttrium vanadate phosphors with Al2 O3
HU200033B (en) * 1988-03-28 1990-03-28 Tungsram Reszvenytarsasag Method for making luminous powder in yellow-green range and mercury vapour gas-discharge lamp containing the said powder

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4585673A (en) * 1984-05-07 1986-04-29 Gte Laboratories Incorporated Method for coating phosphor particles
WO1991010715A1 (fr) * 1990-01-22 1991-07-25 Gte Laboratories Incorporated Phosphores presentant une amelioration du flux lumineux et lampes realisees a partir de ceux-ci

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013103952A2 (fr) * 2012-01-06 2013-07-11 Advanced Lighting Technologies, Inc. Lampe optique intégrée
WO2013103952A3 (fr) * 2012-01-06 2013-12-27 Advanced Lighting Technologies, Inc. Lampe optique intégrée

Also Published As

Publication number Publication date
DE69409265D1 (de) 1998-05-07
DE69409265T2 (de) 1998-12-24
EP0607061A1 (fr) 1994-07-20
CA2113470A1 (fr) 1994-07-16

Similar Documents

Publication Publication Date Title
US4079288A (en) Alumina coatings for mercury vapor lamps
US4924141A (en) Aluminum oxide reflector layer for fluorescent lamps
JP3078523B2 (ja) 可視光発生方法
US6049164A (en) Low-pressure mercury lamp with specific electrode screens
EP0067030B1 (fr) Lampe fluorescente
US3569762A (en) Electron discharge lamps with rare earth phosphor coating
EP0607061B1 (fr) Lampe à décharge de grande intensité
US3541376A (en) Fluorescent lamp with filter coating of a mixture of tio2 and sb2o3
US7719177B2 (en) Low-pressure mercury vapor discharge lamp and compact fluorescent lamp
US4988914A (en) Red fluorescent lamp suitable for reprographic applications
KR100478304B1 (ko) 형광 램프 및 조명장치
JP2001319619A (ja) 蛍光ランプ
GB2115977A (en) High efficacy fluorescent/arc discharge light source
JP3861557B2 (ja) 蛍光ランプ
JPH11339722A (ja) 管球およびこの管球を用いた照明器具
JP3376670B2 (ja) けい光ランプおよびこれを用いた照明装置
Preston et al. Metal halide lamps
JP4421172B2 (ja) メタルハライドランプ
EP1323181B1 (fr) Lampe a decharge basse pression a tres haute puissance (vho)
JP3343362B2 (ja) ラピッドスタ−ト形けい光ランプ
EP0907961B1 (fr) Lampe a mercure a basse pression
JP2000348679A (ja) 蛍光ランプおよび照明装置
JPH06287552A (ja) 混合蛍光体および蛍光ランプ
EP0042230A1 (fr) Lampes à décharge de grande intensité
JP2000133207A (ja) ラピッドスタート形蛍光ランプおよびその製造方法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): BE DE FR GB NL

17P Request for examination filed

Effective date: 19940928

17Q First examination report despatched

Effective date: 19960904

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE DE FR GB NL

REF Corresponds to:

Ref document number: 69409265

Country of ref document: DE

Date of ref document: 19980507

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 20020108

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20020110

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20020131

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20020328

Year of fee payment: 9

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030117

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030131

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20030131

Year of fee payment: 10

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030801

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030801

GBPC Gb: european patent ceased through non-payment of renewal fee
NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20030801

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040930

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST