EP0507533A2 - Quecksilberfreie elektrodenlose Metallhalogenidlampe - Google Patents

Quecksilberfreie elektrodenlose Metallhalogenidlampe Download PDF

Info

Publication number
EP0507533A2
EP0507533A2 EP92302784A EP92302784A EP0507533A2 EP 0507533 A2 EP0507533 A2 EP 0507533A2 EP 92302784 A EP92302784 A EP 92302784A EP 92302784 A EP92302784 A EP 92302784A EP 0507533 A2 EP0507533 A2 EP 0507533A2
Authority
EP
European Patent Office
Prior art keywords
metal halide
mercury
halide lamp
arc
tube
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Withdrawn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
EP92302784A
Other languages
English (en)
French (fr)
Other versions
EP0507533A3 (en
Inventor
Akihiro Inoue
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.)
Toshiba Lighting and Technology Corp
Original Assignee
Toshiba Lighting and Technology Corp
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 Toshiba Lighting and Technology Corp filed Critical Toshiba Lighting and Technology Corp
Publication of EP0507533A2 publication Critical patent/EP0507533A2/de
Publication of EP0507533A3 publication Critical patent/EP0507533A3/en
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J65/00—Lamps without any electrode inside the vessel; Lamps with at least one main electrode outside the vessel
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/82—Lamps with high-pressure unconstricted discharge having a cold pressure > 400 Torr
    • H01J61/827—Metal halide arc lamps
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/24—Means for obtaining or maintaining the desired pressure within the vessel
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/30—Vessels; Containers
    • H01J61/35—Vessels; Containers provided with coatings on the walls thereof; Selection of materials for the coatings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J65/00—Lamps without any electrode inside the vessel; Lamps with at least one main electrode outside the vessel
    • H01J65/04—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels
    • H01J65/042—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels by an external electromagnetic field

Definitions

  • the present invention relates to a mercury-free electrodeless metal halide lamp.
  • mercury-free electrodeless metal halide lamps have been developed and are disclosed in U.S. Patent No. 4,810,938.
  • the mercury-free electrodeless metal halide lamps are classified as high intensity discharge lamps (HID) because their basic operations, each of which is called a discharge, are similar to those of original HID lamps.
  • Metal vapor in each mercury-free electrodeless metal halide lamp is caused to emit visible light upon excitation, typically caused by passage of current through an ionizable gas such as mercury or sodium vapor within the lamp.
  • the conventional HID lamp has a pair of electrodes in an arc discharge tube and the discharge of the conventional HID lamp is caused between the pair of electrodes.
  • the mercury-free electrodeless metal halide lamp described above does not have any electrode in its arc discharge tube. It has, for example, a solenoid coil outside the arc discharge tube to generate a discharge in the arc discharge tube. Further the mercury-free electrodeless metal halide lamp does not use mercury vapor for causing the discharge, which is different from the original HID lamp.
  • One of these problems is an increase of an arc voltage of the lamp during its lifetime.
  • the inventor of the present invention has first recognized this problem in the mercury-free electrodeless metal halide lamp as more significant compared with the problem in the conventional HID lamp.
  • the present invention provides a mercury-free electrodeless metal halide lamp comprising an arc discharge tube.
  • the arc discharge tube is made of glass having an inner surface defining an arc discharge space.
  • a metal oxide layer is coated on the inner surface of the arc discharge tube.
  • the arc discharge space is filled with a filling gas including metal halide and a rare gas.
  • Excitation means may be provided for coupling radio-frequency energy to the filling gas for generating an arc discharge.
  • FIGURE 1 is a cross-sectional view of a metal halide lamp according to a first embodiment of the present invention.
  • FIGURE 2 is a cross-sectional view of a metal halide lamp according to a second embodiment of the present invention.
  • the inventor of the present invention has extensively researched the reasons why the arc voltage of mercury-free electrodeless metal halide lamps more significantly increases during their lifetime as compared with that of an original HID lamp.
  • the believed mechanism for this is as follows.
  • the mercury-free electrodeless metal halide lamp uses a rare gas such as xenon as a replacement for mercury of the original HID lamp. This means that the density of gas in an arc tube of the mercury-free electrodeless metal halide lamp is lower than that of the original HID lamp.
  • the energy level of the metal ions of the mercury-free electrodeless metal halide lamps is higher than that of the original HID lamps. Metal ions having high energy are likely to strike and be adsorbed into the wall of the tube, as compared with those having low energy.
  • metal ions of the mercury-free electrodeless metal halide lamps have higher energy near walls of the tubes than at center portions of the tubes. This relationship is different from that of the original HID lamps. Therefore, metal ions of the mercury-free electrodeless metal halide lamps are more likely to strike against and be adsorbed into the walls of the arc tube than metal ions of the original HID lamps.
  • the inventor of the present invention first contemplated using a barrier of a metal oxide layer for decreasing the adsorbtion of metal ions.
  • FIGURE 1 shows a metal halide lamp according to a typical embodiment of the present invention.
  • the metal halide lamp has an arc tube 21 defining an arc discharge space 23 and is made of transparent quartz glass.
  • Arc tube 21 is formed into a substantially spherical shape and has exhaust tube 25 for exhausting air from arc discharge space 23 and introducing the filling gas therethrough.
  • Arc tube 21 is surrounded by outer electrodes 27 supplying a high frequency electric field to arc tube 21, outer electrodes are connected with high frequency power supply 29.
  • the high frequency electric field has a frequency of 50 megahertz (MHz).
  • the heat conduction of the filling gas from a positive column of an arc discharge to a wall of arc tube 21 is decreased by including the xenon in the filling gas.
  • the low heat conduction of xenon is attributable to the improvement in efficiency.
  • Xenon is present in arc tube 21 at a partial pressure in the range between 60 and 600 Torr at room temperature.
  • the filling gas also includes metal halide such as sodium halide and cerium halide.
  • the metals emit light by the arc discharge.
  • the sodium halide may be sodium iodide (NaI) and the cerium halide may be cerium chloride (CeCl 3 ).
  • Bromide (Br) may be used as the halogen and indium (In), lithium (Li), thallium (Tl) and alkaline earth metals such as barium (Ba), dysprosium (Dy), holmium (Ho) and thulium (Th) may be used as the metals, in addition to, or instead of sodium and cerium.
  • barium Ba
  • Dy dysprosium
  • Ho holmium
  • Th thulium
  • metal oxide layer 31 made of metal oxide grains, and particularly aluminium oxide grains.
  • Metal oxide layer 31 may be made of, for example, rare earth metal oxide grains such as cerium oxide grains or alkaline earth metal oxide grains such as magnesium oxide grains.
  • Metal oxide layer 31 is also formed on an inner surface of exhaust tube 25. The thickness of metal oxide layer 31 is about 3 ⁇ m, but more generally it may be between 1 and 10 ⁇ m.
  • Metal oxide layer 31 is formed by steps as follows. First, a mixture composed of organic dispersant such as butyl acetate and aluminium oxide grains is prepared, particularly ⁇ -nlumina grains dispersed into the organic dispersant. Next, the mixture is introduced into arc tube 21 through exhaust tube 25 which is not sealed and the mixture is coated on the inner surfaces of arc tube 21 and exhaust tube 25. Then an excessive mixture is to be exhausted through exhaust tube 25. After these steps, drying the mixture coated on the inner surface and baking the mixture coated on the surface are carried out. While the mixture is baked at a temperature of about 300 °C to about 700 °C, arc discharge space 23 is ventilated by air and the organic dispersant of the coated mixture is eliminated. Metal oxide layer 31 is formed by eliminating the organic dispersant. Alter these steps described above, steps for exhausting air from arc discharge the 21, introducing a filling gas into arc discharge tube 21 and sealing exhaust tube 25 are carried out and the manufacture of the metal halide lamp is completed.
  • organic dispersant such as butyl
  • Metal oxide layer 31 of the metal halide lamp described above prevents metal ions from directly colliding into or striking against the wall of arc tube 21 and therefore reactions between the metal ions and chemical elements of arc tube 21 decrease. Metal oxide layer 31 is much less likely to react with the metal ions striking thereagainst. Thus, the shortage of metal ions and relative excess of halogen are overcome by metal oxide layer 31, and an increase ratio of a lamp voltage over the lifetime of the metal halide lamp is decreased.
  • the rate of increase of the lamp voltage of the metal halide lamp having metal oxide layer 31 was one third of that of a conventional metal halide lamp not having a metal oxide layer, according to an inventor's experiment. Therefore, it is considered that the rate of the reactions of metal ions with metal oxide layer 31 of the metal halide lamp of the present invention is one third of those with the wall of the arc tube of the conventional lamp.
  • a slow increase of the lamp voltage can also extend the lifetime of the metal halide lamp, because a high voltage to be supplied to a metal halide lamp having a high lamp voltage cannot be obtained by an ordinary operation circuit. Therefore, when the necessary voltage gets higher than can be supplied by the operation circuit, the lamp will fail to begin or maintain discharge. At this time, it can no longer be used, and its useable lifetime is ompleted.
  • the rate of the reactions of metal ions with metal oxide layer 31 of the metal halide lamp of the present invention is lower than those with the wall of the arc tube of the conventional lamp, the disadvantage of coloring metal oxide layer 31 and arc tube 21 of the lamp of the present invention is smaller than that the conventional lamp. Therefore, absorption of light and decrease of luminous flux over the lifetime of the lamp of the present invention is smaller than those of the conventional lamp.
  • An arc discharge needs an initial electron for a start thereof.
  • Metal oxide layer 11, and especially ⁇ -alumina grains have more lattice defects on the surface thereof than the inner surface of arc tube 21 made of quartz. Sometimes, the lattice defect will diminish, and they generally can radiate an electron when the lattice defect diminishes. Electrons radiated from the lattice defects of metal oxide layer 31 work as initial electrons and facilitate the start of the arc discharge.
  • Other metal oxide grains also have lattice defects and can radiate electrons, but aluminium oxide grains are more significant than other metal oxide grains.
  • FIGURE 2 shows a metal halide lamp according to a second embodiment of the present invention.
  • the metal halide lamp of FIGURE 2 is almost the same as that of the first embodiment of Figure 1. The differences are that the metal halide lamp of FIGURE 2 has a fluorescent layer 33 and a smaller region of metal oxide layer 35.
  • the other elements of the second embodiment are similar to those of the first embodiment and therefore, the same reference numerals as those of the first embodiment are given to similar elements to those of the first embodiment.
  • Fluorescent layer 33 is coated on the inner surface of arc tube 21 but not on the inner surface of exhaust tube 25.
  • Metal oxide layer 35 is coated entirely on fluorescent layer 33 and prevents fluorescent layer 33 from being exposed directly to arc discharge space 23.
  • Fluorescent materials of fluorescent layer 33 are more likely to react with metal ions than metal oxide layer 35 and arc tube 21 made of quartz and therefore, metal oxide layer 35 protects fluorescent layer 33.
  • Metal oxide layer 35 does not cover the inner surface of exhaust tube 25, and this facilitates the sealing of exhaust tube 25.
  • exhaust tube 25 is grasped by supporting members 37 in order to flux arc tube 11 between outer electrodes 27.
  • the fluorescent material of fluorescent layer 33 is, for example Y(PV)O 4 :Eu for the purpose of supplementing red light, which is well-knon and well-used for metal halide lamps.
  • the metal halide lamp of the second embodiment described above has the same advantages as the metal halide lamp of the first embodiment.
  • the present invention is not limited to the embodiments described above.
  • the filling gas may include argon in addition to or instead of xenon.
  • the arc tube is not limited to have a spherical shape and may have another shape such a cylindrical shape or an elliptical shape.
  • a solenoid coil may be used for supplying a high frequency electric field to an arc tube of the present invention, or alternately an electronic-type ballast could be used.
  • Metal oxide layer 31 of the metal halide lamp of the present invention may be formed by coating and baking metal alkoxide solution such as alumina alkoxide solution instead of using mixture composed of organic dispersant and metal oxide grains.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Electromagnetism (AREA)
  • Discharge Lamps And Accessories Thereof (AREA)
EP19920302784 1991-03-30 1992-03-30 A mercury-free electrodeless metal halide lamp Withdrawn EP0507533A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP3093683A JPH04303549A (ja) 1991-03-30 1991-03-30 高周波点灯式放電ランプ
JP93683/91 1991-03-30

Publications (2)

Publication Number Publication Date
EP0507533A2 true EP0507533A2 (de) 1992-10-07
EP0507533A3 EP0507533A3 (en) 1993-01-07

Family

ID=14089208

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19920302784 Withdrawn EP0507533A3 (en) 1991-03-30 1992-03-30 A mercury-free electrodeless metal halide lamp

Country Status (3)

Country Link
EP (1) EP0507533A3 (de)
JP (1) JPH04303549A (de)
KR (1) KR920018822A (de)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1994027312A1 (en) * 1993-05-12 1994-11-24 Rae Systems, Inc. Gas discharge lamp
EP0660374A1 (de) * 1993-12-24 1995-06-28 Koninklijke Philips Electronics N.V. Niederdruck-Quecksilber-Entladungslampe und Verfahren zur Herstellung derselben
US5561344A (en) * 1993-05-12 1996-10-01 Rae Systems, Inc. Photo-ionization detector for detecting volatile organic gases
US5587626A (en) * 1993-12-10 1996-12-24 General Electric Company Patterned optical interference coatings for only a portion of a high intensity lamp envelope
US5614151A (en) * 1995-06-07 1997-03-25 R Squared Holding, Inc. Electrodeless sterilizer using ultraviolet and/or ozone
EP0674339A3 (de) * 1994-03-25 1997-04-23 Koninkl Philips Electronics Nv Elektrodenlose Niederdruckqueckribberdampfentladungslampe.
NL1003768C2 (nl) * 1995-08-11 1997-11-18 Matsushita Electric Works Ltd Elektrodeloze gasontladingslamp.
EP0903770A3 (de) * 1997-07-21 1999-04-07 Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH Beleuchtungssystem
EP0978134A4 (de) * 1996-12-20 2000-02-09 Fusion Lighting Inc Lampenapparat mit reflektierender, keramischer hülse, der ein lichtemittierendes plasma enthält
US6124683A (en) * 1999-04-14 2000-09-26 Osram Sylvania Inc. System for and method of operating a mercury free discharge lamp
US6229269B1 (en) 1999-05-21 2001-05-08 Osram Sylvania Inc. System for and method of operating a discharge lamp
US8282986B2 (en) 2006-05-18 2012-10-09 Osram Sylvania, Inc. Method of applying phosphor coatings

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1021880A (ja) * 1996-07-08 1998-01-23 Toshiba Lighting & Technol Corp 放電ランプ、照射装置、殺菌装置および水処理装置
JP2000133209A (ja) * 1998-10-27 2000-05-12 Iwasaki Electric Co Ltd 無電極電界放電エキシマランプ装置
KR100367132B1 (ko) * 2000-04-27 2003-01-09 준 최 무전극 방전 장치
MX2013003437A (es) * 2010-09-29 2014-02-27 Neo Tech Aqua Solutions Inc Fuente de luz excimera.

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4492898A (en) * 1982-07-26 1985-01-08 Gte Laboratories Incorporated Mercury-free discharge lamp
US4480213A (en) * 1982-07-26 1984-10-30 Gte Laboratories Incorporated Compact mercury-free fluorescent lamp
US4890042A (en) * 1988-06-03 1989-12-26 General Electric Company High efficacy electrodeless high intensity discharge lamp exhibiting easy starting
US4972120A (en) * 1989-05-08 1990-11-20 General Electric Company High efficacy electrodeless high intensity discharge lamp

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5561344A (en) * 1993-05-12 1996-10-01 Rae Systems, Inc. Photo-ionization detector for detecting volatile organic gases
WO1994027312A1 (en) * 1993-05-12 1994-11-24 Rae Systems, Inc. Gas discharge lamp
US5676579A (en) * 1993-12-10 1997-10-14 General Electric Company Patterned optical interference coatings for electric lamps
US5587626A (en) * 1993-12-10 1996-12-24 General Electric Company Patterned optical interference coatings for only a portion of a high intensity lamp envelope
BE1007914A3 (nl) * 1993-12-24 1995-11-14 Philips Electronics Nv Lagedruk-kwikdampontladingslamp en werkwijze voor het vervaardigen ervan.
US5666027A (en) * 1993-12-24 1997-09-09 U.S. Philips Corporation Low-pressure mercury vapour discharge lamp and method of manufacturing same
EP0660374A1 (de) * 1993-12-24 1995-06-28 Koninklijke Philips Electronics N.V. Niederdruck-Quecksilber-Entladungslampe und Verfahren zur Herstellung derselben
EP0674339A3 (de) * 1994-03-25 1997-04-23 Koninkl Philips Electronics Nv Elektrodenlose Niederdruckqueckribberdampfentladungslampe.
US5614151A (en) * 1995-06-07 1997-03-25 R Squared Holding, Inc. Electrodeless sterilizer using ultraviolet and/or ozone
NL1003768C2 (nl) * 1995-08-11 1997-11-18 Matsushita Electric Works Ltd Elektrodeloze gasontladingslamp.
US5866981A (en) * 1995-08-11 1999-02-02 Matsushita Electric Works, Ltd. Electrodeless discharge lamp with rare earth metal halides and halogen cycle promoting substance
EP0978134A4 (de) * 1996-12-20 2000-02-09 Fusion Lighting Inc Lampenapparat mit reflektierender, keramischer hülse, der ein lichtemittierendes plasma enthält
EP0903770A3 (de) * 1997-07-21 1999-04-07 Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH Beleuchtungssystem
US6069456A (en) * 1997-07-21 2000-05-30 Osram Sylvania Inc. Mercury-free metal halide lamp
US6124683A (en) * 1999-04-14 2000-09-26 Osram Sylvania Inc. System for and method of operating a mercury free discharge lamp
US6229269B1 (en) 1999-05-21 2001-05-08 Osram Sylvania Inc. System for and method of operating a discharge lamp
US8282986B2 (en) 2006-05-18 2012-10-09 Osram Sylvania, Inc. Method of applying phosphor coatings

Also Published As

Publication number Publication date
JPH04303549A (ja) 1992-10-27
KR920018822A (ko) 1992-10-22
EP0507533A3 (en) 1993-01-07

Similar Documents

Publication Publication Date Title
EP0507533A2 (de) Quecksilberfreie elektrodenlose Metallhalogenidlampe
JP2931819B2 (ja) 硫黄又はセレンを有するランプ
US6972521B2 (en) Low-pressure gas discharge lamp having a mercury-free gas filling with an indium compound
EP1428241B1 (de) Niederdruckgasentladungslampe mit quecksilberfreier gasfüllung
EP0207333A1 (de) Elektrodenfreie Hochdrucknatriumiodidbogenlampe
JPH0679472B2 (ja) 高効率無電極高光度放電ランプ
GB1584417A (en) High pressure electrical discharge lamp containing metal halides
JP2002124211A5 (de)
US7057350B2 (en) Metal halide lamp with improved lumen value maintenance
US5032762A (en) Protective beryllium oxide coating for high-intensity discharge lamps
JPH0230054A (ja) 点灯の容易な高効率の無電極形高光度放電ランプ
CN1265421C (zh) 具有下变频发光体的气体放电灯
JP2002020745A (ja) 弗化物蛍光体及びこれを使用した蛍光ランプ
US5363015A (en) Low mercury arc discharge lamp containing praseodymium
JP2001081460A (ja) 紫外発光物質及びこれを使用した紫外線発光蛍光ランプ、紫外発光素子
EP0368958A1 (de) Leuchtstofflichtquelle, basierend auf einem durch molekulare entladung erregten phosphor
JP2004514748A (ja) 蛍光層を備えるガス放電ランプ
CN1265420C (zh) 具有降低转换发光体的气体放电灯
JP2004527637A (ja) ダウンコンバージョン蛍光体を有するガス放電ランプ
US6603267B2 (en) Low-pressure gas discharge lamp with a copper-containing gas filling
CN1384527A (zh) 具有下变频发光体的气体放电灯
WO2006008971A1 (ja) 蛍光体とその製造方法および発光装置
JP4662778B2 (ja) 電灯および蛍光灯
JP3196649B2 (ja) 無電極高圧放電ランプ
CN101213636A (zh) 包括分子辐射体和添加剂的低压放电灯

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

17P Request for examination filed

Effective date: 19920421

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE FR GB

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE FR GB

17Q First examination report despatched

Effective date: 19940805

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: 19941216