EP0803898A2 - Electrode pour lampe à décharge - Google Patents

Electrode pour lampe à décharge Download PDF

Info

Publication number
EP0803898A2
EP0803898A2 EP97106015A EP97106015A EP0803898A2 EP 0803898 A2 EP0803898 A2 EP 0803898A2 EP 97106015 A EP97106015 A EP 97106015A EP 97106015 A EP97106015 A EP 97106015A EP 0803898 A2 EP0803898 A2 EP 0803898A2
Authority
EP
European Patent Office
Prior art keywords
barium
electrode
electrode according
electron emitter
cup
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.)
Withdrawn
Application number
EP97106015A
Other languages
German (de)
English (en)
Other versions
EP0803898A3 (fr
Inventor
Klaus-Dieter Bauer
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.)
Osram GmbH
Original Assignee
Patent Treuhand Gesellschaft fuer Elektrische Gluehlampen mbH
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 Patent Treuhand Gesellschaft fuer Elektrische Gluehlampen mbH filed Critical Patent Treuhand Gesellschaft fuer Elektrische Gluehlampen mbH
Publication of EP0803898A2 publication Critical patent/EP0803898A2/fr
Publication of EP0803898A3 publication Critical patent/EP0803898A3/fr
Withdrawn legal-status Critical Current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
    • H01J61/04—Electrodes; Screens; Shields
    • H01J61/06—Main electrodes
    • H01J61/067—Main electrodes for low-pressure discharge lamps
    • H01J61/0675—Main electrodes for low-pressure discharge lamps characterised by the material of the electrode
    • H01J61/0677—Main electrodes for low-pressure discharge lamps characterised by the material of the electrode characterised by the electron emissive material

Definitions

  • the invention relates to an electrode for discharge lamps according to the preamble of patent claim 1.
  • Such an electrode used in low-pressure discharge lamps is, for example, on pages 137 to 139 of the book Die Oxydkathode ", Volume 2 by G. Hermann and S. Wagener, Johann Ambrosius Verlag, Leipzig, 2nd edition (1950).
  • This electrode has a rod-shaped, double or triple-coiled electrode coil made of tungsten, which is equipped with an electron emitter
  • the standard electron emitter consists of a mixed oxide containing barium, strontium and calcium oxide, which is usually used when activating the electrodes inserted in the lamp from an emitter paste with 45 mol percent barium carbonate, 45 mol percent strontium carbonate and with 10 mol percent calcium carbonate by chemical means
  • the disadvantage of this electrode is that the emitter paste has to be converted from carbonate to oxide because the carbon dioxide produced in this process has to be removed.
  • this electrode when used in cold-starting, that is, without, this electrode has Electrode preheating igniting low discharge lamps have a short lifespan. Furthermore, due to its geometry and dimensions, this electrode coil is only of limited suitability for use in T1 and T2 fluorescent lamps.
  • Swiss patent CH 449 117 discloses a sintered electrode for gas discharge lamps, the electron emitter of which is produced from a mixture of metal powder with oxides or peroxides of the alkaline earth metals. This mixture preferably contains two parts of oxides or peroxides of the alkaline earth metals and one part of metal powder. It is pressed into the electrode body under high pressure, approx. 1000-2000 kg / cm 2 , and then sintered.
  • This patent explicitly mentions barium oxide as the oxide and / or peroxide, and zirconium, tantalum and tungsten are listed as the metal powder. The manufacturing process of this electrode is comparatively complex and the electrode does not show sufficient cold start strength.
  • European patent application EP 0 253 316 discloses cold-startable electrodes for low-pressure discharge lamps, which essentially consist of a semiconducting porcelain.
  • the main component of these electrodes contains one or more oxides of the elements titanium, barium, strontium, calcium, lanthanum and tin. They also have one or more additives from the group Y, Dy, Hf, Ce, Pr, Nd, Sm, Gd, Ho, Er, Tb, Sb, Nb, W, Yb, Sc and Ta.
  • the production of these electrodes is too expensive.
  • these electrodes are only suitable for low-pressure discharge lamps with comparatively low operating currents of up to approx. 50 mA, but not for operating currents of more than 100 mA as they occur in conventional fluorescent lamps.
  • the electrode according to the invention is provided with an electron emitter which contains a barium compound from the group barium zirconate, barium hafnate, barium titanate and barium cerate as the main constituent and also has metallic additives, preferably from the group zirconium, hafnium, iron, nickel, niobium and tantalum. These barium compounds are characterized by their high chemical stability compared to barium oxide.
  • the electrode according to the invention is activated, there is no violent gas evolution as in the case of the carbonate pastes mentioned above, since the barium zirconate or barium hafnate or barium titanate or barium cerate does not decompose during this process.
  • Barium zirconate BaZrO 3 has proven to be particularly advantageous.
  • the metallic additives in the emitter act as reducing agents. They produce excess free metallic barium in barium zirconate or barium hafnate or barium titanate or barium cerate, which gives the emitter semiconducting properties and a low electron work function.
  • the reaction proceeds according to the following scheme: 2 BaZrO 3rd + 1 Me ⁇ 2 ZrO 2nd + MeO 2nd + 2 Ba
  • the excess metallic barium reduces the electron work function of the emitter from approx. 3 eV - corresponding to the value for barium zirconate - to a value of approx. 2 eV.
  • the proportion of barium zirconate in the emitter is advantageously 10 mol percent to 99 mol percent while the proportion of metallic additives is between 1 mol percent and 90 mol percent.
  • Barium zirconate fractions between 40 mole percent and 90 mole percent as well as fractions of the metallic components in the amount of 20 mole percent to 50 mole percent have proven particularly good.
  • the reaction rate of the reduction taking place in the above-mentioned reaction scheme can also be positively influenced by adding oxides to the emitter.
  • oxides in some preferred embodiments of the electrode according to the invention, zirconium dioxide and / or calcium oxide are advantageously added to the emitter in order to reduce the reaction rate.
  • the proportion of these oxides in the electron emitter can advantageously be up to 50 mole percent.
  • calcium zirconate was advantageously added to the emitter to further reduce the electron work function.
  • the barium zirconate was partially replaced by strontium zirconate.
  • the metallic reducing agents also give rise to free excess metallic strontium which, according to an analogous reaction scheme, similar to that described above for barium zirconate, produces the electron work function of the emitter lowers and gives the emitter semiconducting properties.
  • the grain size of the emitter constituents also has an influence on the above-described reaction in which the excess metallic barium is formed. It is advantageously between 1 ⁇ m and 20 ⁇ m.
  • the electrode according to the invention is advantageously designed as a cold-startable cup electrode, which has a cup-like vessel with a power supply attached to it.
  • the electrode according to the invention can also be used in T1 and T2 fluorescent lamps whose tubular discharge vessel has a diameter of only about 1/8 inch or 2/8 inch, ie, 3.2 mm or 6.4 mm, and therefore no assembly with the rod coils normally used is permitted.
  • the electrode according to the invention is particularly well suited for use in compact fluorescent lamps, which are now commercially available as an energy-saving replacement for the general-purpose incandescent lamp.
  • the electrodes according to the invention have a high switching stability.
  • the emitter is attached to the inner wall of the cup-like vessel or, in a particularly preferred exemplary embodiment, fills the spaces between a helix which is arranged in the interior of the cup-like vessel.
  • the winding axis of this coil advantageously runs parallel to the cup axis, so that the windings of the coil with a clamp fit against the inside wall of the cup. This minimizes possible blackening of the lamp bulb due to sputtering and evaporating emitter material.
  • the cup-like vessel of the electrode according to the invention advantageously consists of a high-melting metal from the group of niobium, tantalum, molybdenum, iron and nickel.
  • the electrode coil arranged in the cup is advantageously made from tantalum, molybdenum or niobium.
  • FIG. 1 shows the structure of the electrode according to the invention in accordance with exemplary embodiments 1 to 4.
  • These electrodes are a cup electrode for a T2 fluorescent lamp.
  • These electrodes have a cup-like vessel 1 made of niobium, in the bottom of which a power supply 2 is attached.
  • the cup-like vessel 1 is formed from a sheet which is squeezed over the power supply 2.
  • the outer diameter of the cup-like vessel 1 is approximately 2 mm, its height is approximately 3.5 mm and its wall thickness is approximately 0.3 mm.
  • the electron emitter 3 is arranged on the inner wall of the cup-like vessel 1.
  • the electron emitter 3 consists of 40 mole percent barium zirconate BaZrO 3 , which is mixed with 30 mole percent zirconium Zr, 25 mole percent zirconium dioxide ZrO 2 and 5 mole percent calcium oxide CaO.
  • the electron emitter 3 consists of 40 mol percent barium zirconate BaZrO 3 , that with 20 mol percent calcium zirconate CaZrO 3 , 20 mole percent zirconium Zr and 20 mole percent zirconium dioxide ZrO 2 is mixed.
  • the electrode according to the third exemplary embodiment has an electron emitter with 50 mol percent barium zirconate BaZrO 3 , to which 30 mol percent iron Fe and 20 mol percent niobium Nb are mixed.
  • the electron emitter of the electrode according to the invention consists of 90 mol percent barium zirconate BaZrO 3 , which is mixed with 10 mol percent hafnium Hf.
  • the electrode of the fifth exemplary embodiment consists of 48 mol percent barium zirconate BaZrO 3 , to which 17 mol percent strontium zirconate SrZrO 3 and 35 mol percent titanium Ti are added.
  • the experimentally determined electron work functions for the emitter compositions according to the exemplary embodiments 1 to 5 are listed for different temperature types.
  • the table also contains corresponding comparison values for the standard emitter cited as prior art.
  • FIG. 2 shows the structure of the electrodes in accordance with exemplary embodiments 6 to 10.
  • These electrodes are also cold startable cup electrodes for a T2 fluorescent lamp.
  • These electrodes have a cup-like vessel 4 made of niobium, in the bottom of which a power supply 5 is fastened.
  • the cup-like vessel 4 is formed from an approximately 0.3 mm thick sheet which is squeezed over the power supply 5.
  • the outer diameter of the cup-like vessel 4 is approximately 2 mm and its height is approximately 3.5 mm.
  • a double helix 6 made of tantalum is arranged in the cup-like vessel 4. The winding axis this helix 6 runs coaxially to the cup axis.
  • the windings of the helix 6 are in an inhibitory manner on the inner wall of the cup-like vessel 4.
  • the electron emitter 7 is arranged on the filament 6 and fills the spaces between the windings of the filament 6 and the spaces between the filament 6 and the inner wall of the cup-like vessel 4.
  • the emitter compositions of the exemplary embodiments 6 to 10 correspond to the emitter compositions of the exemplary embodiments 1 to 5 match.
  • the electrodes of the exemplary embodiments 1 and 6 and 2 and 7 etc. therefore differ only in their structure, but not in the electron emitter.
  • barium zirconate BaZrO 3 with a grain size of approximately 1.2 ⁇ m was used for the electron emitter.
  • the metallic and oxidic additives were ground to a grain size of approx. 5 ⁇ m.
  • the electrodes according to the invention were annealed before use in lamps under an inert gas atmosphere.
  • the cup-like vessel 1, 4 can also consist of molybdenum, tantalum, nickel or iron and the coil 6 can consist of molybdenum, tungsten or niobium.
  • the coil 6 can consist of molybdenum, tungsten or niobium.
  • zirconium, hafnium, niobium and iron, nickel, tantalum, chromium, molybdenum, tungsten and vanadium are also suitable as metallic additives to the electron emitter.
  • barium compounds Bariumhafnat (BaHfO 3), barium titanate (BaTiO 3) can be and barium cerate (BaCeO 3) was used instead of barium zirconate (BaZrO 3).

Landscapes

  • Discharge Lamp (AREA)
  • Luminescent Compositions (AREA)
EP97106015A 1996-04-24 1997-04-11 Electrode pour lampe à décharge Withdrawn EP0803898A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19616408 1996-04-24
DE19616408A DE19616408A1 (de) 1996-04-24 1996-04-24 Elektrode für Entladungslampen

Publications (2)

Publication Number Publication Date
EP0803898A2 true EP0803898A2 (fr) 1997-10-29
EP0803898A3 EP0803898A3 (fr) 1997-12-29

Family

ID=7792333

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97106015A Withdrawn EP0803898A3 (fr) 1996-04-24 1997-04-11 Electrode pour lampe à décharge

Country Status (9)

Country Link
US (1) US5880558A (fr)
EP (1) EP0803898A3 (fr)
JP (1) JPH1050252A (fr)
KR (1) KR970071987A (fr)
CN (1) CN1170954A (fr)
CA (1) CA2203330A1 (fr)
DE (1) DE19616408A1 (fr)
HU (1) HU218818B (fr)
TW (1) TW320733B (fr)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1037244A3 (fr) * 1999-03-12 2003-01-08 TDK Corporation Matériau émetteur d'électrons et son procédé de préparation
CN1386294A (zh) 2000-05-12 2002-12-18 皇家菲利浦电子有限公司 高压放电灯
JP2002289139A (ja) * 2001-03-28 2002-10-04 Matsushita Electric Ind Co Ltd 冷陰極放電ランプ
DE10122392A1 (de) * 2001-05-09 2002-11-14 Philips Corp Intellectual Pty Gasentladungslampe
US6603249B2 (en) * 2001-09-24 2003-08-05 Osram Sylvania Inc. Fluorescent lamp with reduced sputtering
DE10242241A1 (de) * 2002-09-12 2004-03-25 Philips Intellectual Property & Standards Gmbh Niederdruckgasentladungslampe mit Ba TiO3-ähnlichen Elektronen-Ermittersubstanzen
CN1306554C (zh) * 2004-04-20 2007-03-21 陈宗烈 无灯丝热阴极荧光灯
US7633226B2 (en) * 2005-11-30 2009-12-15 General Electric Company Electrode materials for electric lamps and methods of manufacture thereof
US8253331B2 (en) * 2010-04-28 2012-08-28 General Electric Company Mercury dosing method for fluorescent lamps
CN104091740A (zh) * 2014-01-24 2014-10-08 朱惠冲 高强度稀土钼管冷阴极及其制备工艺
CN109686515B (zh) * 2018-12-30 2021-02-12 苏州团芯终端有限公司 高可靠性的ptc热敏电阻

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2687489A (en) * 1952-06-26 1954-08-24 Hanovia Chemical & Mfg Co Electrode
CH449117A (de) * 1964-07-08 1967-12-31 Elin Union Ag Verfahren zur Herstellung von gesinterten Elektroden
US3558964A (en) * 1968-10-21 1971-01-26 Gen Electric High current thermionic hollow cathode lamp
US4081713A (en) * 1976-01-28 1978-03-28 Hitachi, Ltd. Directly heated oxide cathode
US4210840A (en) * 1978-12-12 1980-07-01 Westinghouse Electric Corp. HID Lamp emission material
US5278474A (en) * 1989-01-12 1994-01-11 Tokyo Densoku Kabushiki Kaisha Discharge tube
US5304893A (en) * 1990-07-19 1994-04-19 Tokyo Densoku Kabushiki Kaisha Discharge tube having cup shape glow discharge electrode
EP0738423B1 (fr) * 1994-11-08 1999-01-13 Koninklijke Philips Electronics N.V. Lampe a decharge basse pression

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4105908A (en) * 1976-04-30 1978-08-08 General Electric Company Metal halide lamp having open tungsten coil electrodes
KR900008794B1 (ko) * 1986-06-11 1990-11-29 티 디 케이 가부시끼가이샤 방전 램프장치
KR920001844B1 (ko) * 1986-07-15 1992-03-05 티디 케이 가부시기가이샤 냉음극형 방전 등 장치
JP2628314B2 (ja) * 1987-09-18 1997-07-09 ティーディーケイ株式会社 冷陰極型放電灯装置
JP2881479B2 (ja) * 1990-06-08 1999-04-12 ティーディーケイ株式会社 放電電極
JPH04272109A (ja) * 1991-02-27 1992-09-28 Toshiba Corp 冷陰極蛍光ランプ用電極材料およびそれからなる電極
JPH0684579A (ja) * 1991-12-26 1994-03-25 American Teleph & Telegr Co <Att> ガスチューブ保護装置
FR2701597B1 (fr) * 1993-02-16 1995-05-19 Jacques Villain Cathode froide pour tube à décharge dans un gaz avec une couche de composé d'alcalino-terreux sur un support métallique.
JPH07142027A (ja) * 1993-11-17 1995-06-02 Noritake Co Ltd 放電管
US5627430A (en) * 1994-06-29 1997-05-06 Ushiodenki Kabushiki Kaisha Discharge lamp having a cathode with a sintered tip insert

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2687489A (en) * 1952-06-26 1954-08-24 Hanovia Chemical & Mfg Co Electrode
CH449117A (de) * 1964-07-08 1967-12-31 Elin Union Ag Verfahren zur Herstellung von gesinterten Elektroden
US3558964A (en) * 1968-10-21 1971-01-26 Gen Electric High current thermionic hollow cathode lamp
US4081713A (en) * 1976-01-28 1978-03-28 Hitachi, Ltd. Directly heated oxide cathode
US4210840A (en) * 1978-12-12 1980-07-01 Westinghouse Electric Corp. HID Lamp emission material
US5278474A (en) * 1989-01-12 1994-01-11 Tokyo Densoku Kabushiki Kaisha Discharge tube
US5304893A (en) * 1990-07-19 1994-04-19 Tokyo Densoku Kabushiki Kaisha Discharge tube having cup shape glow discharge electrode
EP0738423B1 (fr) * 1994-11-08 1999-01-13 Koninklijke Philips Electronics N.V. Lampe a decharge basse pression

Also Published As

Publication number Publication date
CA2203330A1 (fr) 1997-10-24
EP0803898A3 (fr) 1997-12-29
US5880558A (en) 1999-03-09
TW320733B (fr) 1997-11-21
HU9700799D0 (en) 1997-06-30
CN1170954A (zh) 1998-01-21
HU218818B (hu) 2000-12-28
KR970071987A (ko) 1997-11-07
HUP9700799A3 (en) 1999-10-28
JPH1050252A (ja) 1998-02-20
DE19616408A1 (de) 1997-10-30
HUP9700799A2 (hu) 1998-04-28

Similar Documents

Publication Publication Date Title
EP0652586B1 (fr) Lampe à décharge à halogénure de métal avec récipient de décharge en céramique et son procédé de fabrication
DE10291427B4 (de) Halogen-Metalldampflampe für einen Kraftfahrzeugscheinwerfer
DE2753039C2 (de) Elektrode für eine Entladungslampe
DE2626700A1 (de) Hochdruckgasentladungslampe und verfahren zu ihrer herstellung
DE2161173B2 (de) Oxydelektrode für elektrische Hochleistungs-Gasentladungslampen
DE69731374T2 (de) Niederdruckentladunglampe
EP0803898A2 (fr) Electrode pour lampe à décharge
DE1911985C3 (de) Hochdruck-Bogenentladungslampe
DE2951741A1 (de) Elektrode fuer eine entladungslampe
DE3050460C2 (de) Elektrische Blitzlampe
DE69921901T2 (de) Cermet und keramische Entladungslampe
EP1032022B1 (fr) Lampe à halogénure métallique avec enveloppe céramique
DE19913867A1 (de) Dielektrische Keramik und dieselbe verwendender Kondensator
EP1104933A2 (fr) Lampe à décharge à gaz à électrode pourvu d&#39;un émetteur à oxyde
DE69915966T2 (de) Niederdruck-Quecksilberdampfentladungslampe
DE944621C (de) Anktivierungsmaterial fuer Elektroden von elektrischen Entladungsgefaessen
DE2845283C2 (fr)
DE2849606C3 (de) Basismetallplattenmaterial für direkt erhitzte Oxidkathoden
DE2714539A1 (de) Elektroden einer hochdruck-quecksilberdampf-entladungslampe
EP0592915B1 (fr) Lampe à décharge à basse pression et procédé de production d&#39;un lampe à décharge à basse pression
DE10044451C1 (de) Elektrode und Kondensator mit der Elektrode
EP0759633B1 (fr) Lampe à décharge à haute pression
DE69911538T2 (de) Niederdruckquecksilberdampfentladungslampe
DE2935447C2 (de) Direkt beheizte Sinterelektrode
DE3119747A1 (de) Emittierende masse und verfahren zu ihrer herstellung

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: A2

Designated state(s): BE DE ES FR GB IT NL SE

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): BE DE ES FR GB IT NL SE

17P Request for examination filed

Effective date: 19980121

17Q First examination report despatched

Effective date: 19990909

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

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20010620