EP0159741A1 - Lampe à décharge à vapeur de sodium à haute pression - Google Patents

Lampe à décharge à vapeur de sodium à haute pression Download PDF

Info

Publication number
EP0159741A1
EP0159741A1 EP85200448A EP85200448A EP0159741A1 EP 0159741 A1 EP0159741 A1 EP 0159741A1 EP 85200448 A EP85200448 A EP 85200448A EP 85200448 A EP85200448 A EP 85200448A EP 0159741 A1 EP0159741 A1 EP 0159741A1
Authority
EP
European Patent Office
Prior art keywords
lamp
lamps
pressure sodium
sodium
emitter
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Withdrawn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
EP85200448A
Other languages
German (de)
English (en)
Inventor
Johannis De Kok
Jan Rudolf De Bie
Antonius Driessen
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.)
Koninklijke Philips NV
Original Assignee
Philips Gloeilampenfabrieken NV
Koninklijke Philips Electronics NV
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 Philips Gloeilampenfabrieken NV, Koninklijke Philips Electronics NV filed Critical Philips Gloeilampenfabrieken NV
Publication of EP0159741A1 publication Critical patent/EP0159741A1/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Withdrawn legal-status Critical Current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
    • H01J61/073—Main electrodes for high-pressure discharge lamps
    • H01J61/0735—Main electrodes for high-pressure discharge lamps characterised by the material of the electrode
    • H01J61/0737—Main electrodes for high-pressure discharge lamps characterised by the material of the electrode characterised by the electron emissive material
    • 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
    • H01J61/073—Main electrodes for high-pressure discharge lamps

Definitions

  • the invention relates to a high-pressure sodium vapour discharge lamp provided with a lamp vessle sealed in a vacuum-tight manner and containing sodium, mercury and rare gas, while current supply conductors are passed through the wall of the lamp vessel to a pair of electrodes having a strontium-containing emitter.
  • Such a lamp is known form Britisch Patent Specification 2,051,470 (PHN 9472) .
  • the known lamp is constructed so that it emits during operation substantially "white light", i.e. light having a colour temperature lying between approximately 2250 and approximately 2750 K and a general colour rendition index Ra 8 lying between approximately 60 and approcimately 85.
  • the emitter of the electrodes contains oxygen-bound strontium and oxygen-bound tungsten in a molar ratio of 3 to 50. This emitter is used in the known lamps because such an emitter counteracts the extraction of sodium from the discharge.
  • the temperature of the sodium amalgam in high-pressure sodium lamps also increases as their power is lower. This is due to the smaller dimensions of low-power lamps.
  • the temperature of the sodium amalgam in a high-pressure sodium lamp of 50 W emitting "white light" is approximately 1200 K.
  • the invention has for its object to provide a high-pressure sodium lamp which, even if it is dresigned to emit "white light" at very low power, has a longer life sufficient for practical use.
  • this object is achieved in a high-pressure sodium vapour discharge lamp of the kind mentioned in the opening paragraph in that the emitter comprises strontium yttrate.
  • the lamp according to the invention even if it is designed so that during operation very high temperatures prevail in it, such as, for example, a lamp generating "white light” and consuming 50 W, has a considerably longer life sufficient for practical use.
  • the end of the life of high-pressure sodium lamps is attained when the voltage across the lamp has increased to such an extent that the lamp extinguishes or, in lamps designed to emit "white light", when the colour point of the emitted light shifts to outside the range in the colour triangle within which the light is "white”. Both this shift of the colour point and the increase of the lamp voltage are caused by the fact that the ratio Na/Hg in the filling of the lamp descreases as a result of sodium being extracted from the filling.
  • the colour temperature then lies betweent about 2300 and about 2700 K and the general colour rendition index Ra 8 lies between about 70 and about 85.
  • the high-pressure sodium lamp according to the invention is obtained inter alia by immersing electrodes in a suspension of SrCO 3 and Y 2 O 3 . After they have been dried, the electrodes are heated to form the emiter in situ. A heating at about 1600°C for a few, for example two, minutes in vacuo or in a inert gas is sufficient to this end.
  • the emitter has the advantage that it is highly resistant to the action of moisture so that electrodes provided with the emitter can be manipulated in contact with the prevailing atmosphere.
  • strontium carbonate instead of strontium carbonate another strontium salt, such as the formiate maybe utilized or, for example, strontium hydroxide or peroxide may be used.
  • strontium hydroxide or peroxide instead of strontium carbonate another strontium salt, such as the formiate maybe utilized or, for example, strontium hydroxide or peroxide may be used.
  • strontium hydroxide or peroxide instead of strontium carbonate another strontium salt, such as the formiate maybe utilized or, for example, strontium hydroxide or peroxide may be used.
  • strontium hydroxide or peroxide may be used.
  • a further possibility is to use a number of stontium compounds.
  • the lamp according to the invention mostly has a ceramic lamp vessel, i.e. a lamp vessel of mono- or polycrystalline material, such as, for example, aluminium oxide.
  • the lamp vessel may have, if the lamp has to emit "white" light, a gas filling containing a sodium amalgam whose weight ratio Na/Hg is 1-1/9, while the pressure of the rare gas, for example xenon and/or argon and/or neon, at 300 K is 1.3 x 10 3 - 1.3 x 10 5 Pa. The sodium pressure during operation is then 4 x 10 4 - 10.7 x 1 0 4 Pa .
  • a ceramic lamp vessel 3 sealed in a vacuum-tight manner is arranged in a glass outer bulb 1 provided with a lamp cap 2 and between current supply conductors 4 and 5.
  • Niobium sleeves 6 and 7 conduct the current through the wall of the lamp vessel to the electrode pair.
  • the current supply conductor 5 is passed with a certain amount of clearance into the niobium sleeve 6. A good electrical contact between these two parts is guaranteed by a Litze wire 8.
  • a glow starter 10 is arranged in the outer bulb in series with a bi-metal switch 11, which together shunt the discharge path in the discharge vessel 3. Upon ignition of the lamp, a glow discharge is obtained in the glow starter 10. After this glow discharge has been extinguished due to increase in temperature in the glow starter, a voltage pulse is produced across the discharge vessel 3, which causes the lamp to ignite. The heat emitted by the discharge opens the bi-metal switch 11.
  • the lamp vessel 3 is sealed at its end by a ring 15 of ceramic material.
  • the sleeve 6 has welded to it a tungsten electrode 17, onto which a tungsten wire 18 is wound which surrounds an emitter 19.
  • a discharge vessel has an inner dianeter of 3,5 mm and an inner lenght of 25 mm. The distance between the tips of the electrodes was 15 mm. 2 mg of emitter was provided on each of the electrodes in the cavities of the wirre turns.
  • the discharges vessel contained 10 mg of sodium amalgam with a ratio Na/Hg of 0.375 and xenon up to a pressure of 10 4 Pa at room temperature. During operation the lanp consumed a power of 50 W.
  • Such lamps provided with different emitters were tested according to the schedule: 5.5 hours “on”, 0,5 hour “off”. It has been found that the lamps tested according to this schedule reach the end of their life after a smaller number of hours in operation as a result of an increase of the lamp voltage than with the use of the schedule 0.5 hours "on”, 0.5 hours "off” or with continuous operation.
  • Electrodes were used which were immersed in a suspension of 290 g of SrCO 3 , 220 g of Y 2 O 3 , 100 ml of monoethylglycol ether, 60 ml of butylacetate and 5 g of cellulose nitrate.
  • the electrodes were dried and were then heated in vacuo for 2 minutes at 1590°C. Sry 2 O 4 was then formed.
  • Electrodes were used to which a suspension of 155 g of SrCO 3 , 55 ml of ethylglycol, 23 ml of ethyl alcohol, 5 ml of butylacetate and 1.5 g of nitrocellulose was applied. After the suspension has been dried, the electrodes were heated in vacuo for 2 minutes at 1450°C. The molar ratio of Sr and W in the emitter was about 10.
  • V 1a voltage across the lamp.
  • the lamps of series I were measured after 3000 operating hours. Out of seven lamps utilized, five lamps has a colour point in the said range. The average value of the colour point of these five lamps is indicated in the table. The experiment was terminated at that instant.
  • the lamps of series II were measured after 1500 operating hours. Out of nineteen lamps utilized, thirteen were then left having the average colour point stated in the table. After 2000 operating hours, only four lamps were left.

Landscapes

  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Discharge Lamp (AREA)
EP85200448A 1984-03-28 1985-03-25 Lampe à décharge à vapeur de sodium à haute pression Withdrawn EP0159741A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NL8400966 1984-03-28
NL8400966 1984-03-28

Publications (1)

Publication Number Publication Date
EP0159741A1 true EP0159741A1 (fr) 1985-10-30

Family

ID=19843709

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85200448A Withdrawn EP0159741A1 (fr) 1984-03-28 1985-03-25 Lampe à décharge à vapeur de sodium à haute pression

Country Status (3)

Country Link
EP (1) EP0159741A1 (fr)
JP (1) JPS60218756A (fr)
HU (1) HU189968B (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5111108A (en) * 1990-12-14 1992-05-05 Gte Products Corporation Vapor discharge device with electron emissive material
WO2005098902A3 (fr) * 2004-04-09 2006-03-16 Koninkl Philips Electronics Nv Lampe a vapeur de sodium haute pression
WO2007064570A2 (fr) * 2005-11-28 2007-06-07 General Electric Company Materiaux pour electrodes exempts de baryum destines a des lampes electriques et procedes de fabrication associes

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2316725A1 (fr) * 1975-06-20 1977-01-28 Philips Nv Lampe a decharge dans le gaz a haute pression
DE2951741A1 (de) * 1978-12-29 1980-07-03 Mitsubishi Electric Corp Elektrode fuer eine entladungslampe
GB2051470A (en) * 1979-05-28 1981-01-14 Philips Nv High-pressure sodium discharge lamp

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2316725A1 (fr) * 1975-06-20 1977-01-28 Philips Nv Lampe a decharge dans le gaz a haute pression
DE2951741A1 (de) * 1978-12-29 1980-07-03 Mitsubishi Electric Corp Elektrode fuer eine entladungslampe
GB2051470A (en) * 1979-05-28 1981-01-14 Philips Nv High-pressure sodium discharge lamp

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENTS ABSTRACTS OF JAPAN, vol. 5, no. 141 (E-73)(813), September 5, 1981, page 145 E 73; & JP - A - 56 78057 (MITSUBISHI DENKI K.K.) 26-06-1981 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5111108A (en) * 1990-12-14 1992-05-05 Gte Products Corporation Vapor discharge device with electron emissive material
WO2005098902A3 (fr) * 2004-04-09 2006-03-16 Koninkl Philips Electronics Nv Lampe a vapeur de sodium haute pression
WO2007064570A2 (fr) * 2005-11-28 2007-06-07 General Electric Company Materiaux pour electrodes exempts de baryum destines a des lampes electriques et procedes de fabrication associes
WO2007064570A3 (fr) * 2005-11-28 2008-07-03 Gen Electric Materiaux pour electrodes exempts de baryum destines a des lampes electriques et procedes de fabrication associes
US7633216B2 (en) 2005-11-28 2009-12-15 General Electric Company Barium-free electrode materials for electric lamps and methods of manufacture thereof

Also Published As

Publication number Publication date
JPS60218756A (ja) 1985-11-01
HUT37295A (en) 1985-11-28
HU189968B (en) 1986-08-28

Similar Documents

Publication Publication Date Title
KR20010013367A (fr) Lampe a iodures metalliques
US4864191A (en) Rhenium-containing electrode for a high-pressure sodium discharge lamp
US5905339A (en) Gas discharge lamp having an electrode with a low heat capacity tip
US4636686A (en) Low-pressure mercury vapor discharge lamp provided with an amalgam forming alloy
CN1128579A (zh) 金属卤化物灯
US2769112A (en) Discharge lamp, mount therefor, and method
CA1270893A (fr) Lampe a decharge sous vapeur de sodium haute pression
EP0491420B1 (fr) Lampe à décharge dans la vapeur de mercure à basse pression
EP0995222B1 (fr) Lampe a decharge a vapeur de mercure a basse pression
US4374339A (en) High-pressure sodium vapor discharge lamp
EP0159741A1 (fr) Lampe à décharge à vapeur de sodium à haute pression
US6037714A (en) Hollow electrodes for low pressure discharge lamps, particularly narrow diameter fluorescent and neon lamps and lamps containing the same
US7423379B2 (en) High-pressure gas discharge lamp having tubular electrodes
US4322654A (en) High-pressure sodium vapor discharge lamp
US5982097A (en) Hollow electrodes for low pressure discharge lamps, particularly narrow diameter fluorescent and neon lamps and lamps containing the same
US4924146A (en) Unsaturated high-pressure sodium lamp
GB2138202A (en) Discharge lamp
EP0110248B1 (fr) Lampe à sodium à haute pression à rendement amélioré
JPH048896B2 (fr)
US4420708A (en) High-pressure sodium vapor discharge lamp
US6268696B1 (en) Mercury and lead free high pressure sodium lamp
EP0523782B1 (fr) Lampe à décharge dans la vapeur de sodium à haute pression
NL7904158A (nl) Hogedruknatriumdamp-ontladingslamp.
EP0110249B1 (fr) Lampe à sodium à haute pression à reproduction améliorée de couleurs
EP0596676B1 (fr) Lampe à décharge dans le sodium à haute pression

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

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

17P Request for examination filed

Effective date: 19860425

17Q First examination report despatched

Effective date: 19870810

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: 19880420

RIN1 Information on inventor provided before grant (corrected)

Inventor name: DRIESSEN, ANTONIUS

Inventor name: DE BIE, JAN RUDOLF

Inventor name: DE KOK, JOHANNIS