EP0479259A2 - Lampe à décharge dans la vapeur de mercure - Google Patents

Lampe à décharge dans la vapeur de mercure Download PDF

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Publication number
EP0479259A2
EP0479259A2 EP91116800A EP91116800A EP0479259A2 EP 0479259 A2 EP0479259 A2 EP 0479259A2 EP 91116800 A EP91116800 A EP 91116800A EP 91116800 A EP91116800 A EP 91116800A EP 0479259 A2 EP0479259 A2 EP 0479259A2
Authority
EP
European Patent Office
Prior art keywords
mercury
carrier
main body
bulb
carrier main
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Withdrawn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
EP91116800A
Other languages
German (de)
English (en)
Other versions
EP0479259A3 (en
Inventor
Hidenori Ito
Takashi Yorifuji
Atsushi Sato
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 EP0479259A2 publication Critical patent/EP0479259A2/fr
Publication of EP0479259A3 publication Critical patent/EP0479259A3/en
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/12—Selection of substances for gas fillings; Specified operating pressure or temperature
    • H01J61/18—Selection of substances for gas fillings; Specified operating pressure or temperature having a metallic vapour as the principal constituent
    • H01J61/20—Selection of substances for gas fillings; Specified operating pressure or temperature having a metallic vapour as the principal constituent mercury vapour
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/38—Exhausting, degassing, filling, or cleaning vessels
    • H01J9/395—Filling vessels
    • 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
    • H01J61/28—Means for producing, introducing, or replenishing gas or vapour during operation of the lamp

Definitions

  • This invention relates to a mercury vapor discharge lamp and a mercury carrier to be used for such a discharge lamp as well as to a method of manufacturing the same. More particularly, the present invention relates to a mercury discharge lamp that contains an accurate amount of sealed-in mercury and a mercury carrier to be used for such a discharge lamp and capable of stably maintaining the mercury as well as to an efficient method of manufacturing the same.
  • a mercury vapor discharge lamp such as a so-called fluorescent lamp has a bulb which is hermetically sealed and contains mercury vapor in it.
  • the amount of sealed-in mercury in the bulb should be accurately controlled so that the lamp may properly work. If the amount of sealed-in mercury in the bulb is smaller than the proper value, the lamp would fall short of the intended output level and service life.
  • a mercury doser is used to deliver a given amount mercury into a bulb.
  • a mercury doser is an apparatus having a small nozzle through which a given amount of mercury is discharged and poured into a bulb for each operation. Since mercury has a large surface tension, however, the mercury discharged from the nozzle can easily cohere to become globular, making the amount of mercury to be poured into the bulb not precisely controllable.
  • the amalgam is heated, it discharges mercury vapor until the partial pressure of the mercury vapor in the bulb reaches a threshold value, when the inside of the bulb is saturated with mercury vapor and the discharge of mercury vapor stops.
  • the saturation vapor pressure of mercury is a function of temperature and rises as the temperature in the bulb goes up.
  • the pressure of mercury vapor in the bulb is low.
  • the pressure may be further reduced when the temperature of ambient air is low and become so low that the lamp would not be activated if the switch of the lamp is turned on.
  • mercury amalgam is normally costly to make the cost of discharge lamps containing such amalgam rather high.
  • a mercury carrier disclosed in the document is prepared by mixing mercury and fine particles of a metallic material such as iron or an iron-nickel alloy that does not form an amalgam with mercury, compressing the mixture of mercury and metallic fine particles in a mold to force out any excessive mercury and bonding the metallic particles together under pressure to make the mixture very solid.
  • a mercury carrier prepared in this way contains liquid mercury in the gaps formed among the pressure bonded metallic particles. The saturation vapor pressure of mercury discharged from such a mercury carrier is relatively high and hence a mercury vapor discharge lamp comprising such a mercury carrier is free from the amalgam-related problem as described above.
  • a mercury carrier having a configuration as described above has a disadvantage that its mechanical strength is relative low and therefore subject to damage during transportation and handling. It is also accompanied by a disadvantage that it can only poorly hold liquid mercury in the gaps among the metallic particles and therefore the liquid mercury contained in the gaps can ooze out onto the surface of the carrier during storage and handling.
  • a mercury carrier to be used for a discharge lamp comprising a porous carrier main body made of an inorganic material such as metal or ceramic.
  • the carrier main body is prefabricated and the air contained in the gaps of the main body is removed in vacuum before it is immersed in a volume of liquid mercury, which is compressed until the gaps in the carrier main body are filled with mercury.
  • a mercury carrier prepared in this way has an enhanced mechanical strength and the amount of mercury with which the gaps in the mercury carrier main body is filled can be rigorously controlled so that it may securely hold the mercury in it.
  • a mercury vapor discharge lamp prepared by using a mercury carrier according to the invention contains in its bulb an accurate amount of mercury and therefore operates very well.
  • a mercury carrier is placed close to the electrodes of the discharge lamp so that it may discharge mercury vapor into the bulb by the heat generated in the bulb when the lamp is energized.
  • the mercury carrier is put into a exhaust pipe of the discharge lamp so that it may discharge mercury vapor into the bulb by the heat generated when the exhaust pipe is pinch-sealed.
  • Fig. 1 illustrates a first embodiment of the mercury vapor discharge lamp of the invention, which is in fact a fluorescent lamp and has a straight tubular bulb 1.
  • the inner surface of the bulb 1 is coated with a fluorescent film 2.
  • a stem 3 is sealed in an end of the bulb 1 and an exhaust pipe 4, a pair of lead wires 5, 5 and filament electrodes 6 are securely fitted to the stem 3.
  • a mercury carrier 71 is securely fitted to the lead wires 5, 5 near the filament electrodes 6.
  • the mercury carrier 71 is realized as an oblong and flat plate.
  • the mercury carrier 71 is constituted by a carrier main body 63, which is made of a porous inorganic material.
  • the carrier main body 63 is prepared by sintering a body of aggregated particles 61 of an inorganic material and contains small drops of liquid mercury in the gaps 61 formed by neighboring particles 61 of the carrier main body 63. The drops of mercury are held in there because of their surface tension.
  • Materials that can be used for preparing the particles 61 include ceramic materials such as aluminum nitride, aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, yttrium oxide and vitreous materials.
  • a carrier main body 63 formed by particles 61 of a ceramic material is electrically highly insulating and therefore can block any electricity trying to flow through the mercury carrier 71 constituted by the main body 63 and arranged between the two lead wires 5, 5 as shown in Fig. 1.
  • Materials that can be used for preparing the particles 61 also include metallic materials.
  • the mercury carrier 71 constituted by such a main body 63 is preferably fitted to a glass section of the stem button of the stem 3 as shown in Fig. 2. With such an arrangement, the lead wires 5, 5 are protected against short-circuiting that can be caused by the conductive mercury carrier 71.
  • the carrier main body 63 of the mercury carrier 71 that has discharged the mercury it used to contain is a porous object having a large surface area and hence has a strong adsorbent effect. Therefore, a carrier main body 63 acts as a getter that effectively adsorb gaseous impurities in the bulb 1 after it has discharged the mercury it used to contain. The effect of the getter will be particularly large when a vitreous material is used for the particles 61.
  • a porous mercury carrier constituted by a carrier main body 63 as described above is prepared by sintering an aggregate of fine particles 61, they are firmly bound together to make the mercury carrier 71 mechanically very strong. Consequently, the mercury carrier 71 can be hardly damaged while it is being handled.
  • the carrier main body 63 of a mercury carrier 71 according to the invention contains mercury in the gaps within it, the amount of mercury contained in it can be accurately controlled. This means that, when properly controlled, a mercury carrier 71 according to the invention contains no excessive mercury that can ooze out from the gaps 61 where it is stored and come to the surface.
  • a mercury carrier 71 according to the invention can be manufactured in the following manner. Firstly, a given amount of a granular material is mixed well and compressed in a mold. The molded material is then sintered to form a carrier main body 63 that constitutes a mercury carrier 71.
  • the carrier main body 63 is heated in steam or a gaseous mixture of steam and hydrogen to remove carbon and other unnecessary substances contained in it.
  • the carrier main body 63 is further heated in vacuum to eliminate moisture and other impurities contained in it as well as air stored in the gaps of the main body.
  • the carrier main body 63 is immersed in liquid mercury in a vacuum chamber and the liquid mercury is put under pressure to a given pressure level. The pressure drives small drops of mercury to get deep into the gaps of the carrier main body 63, where they are retained because of their surface tension.
  • the size and the density of distribution of the gaps in the carrier main body 63 can be controlled by selecting the particle size of the material of the carrier main body 63 and the bulk density of the molded material. Moreover, the extent to which the gaps are filled with mercury can be controlled by selecting the pressure applied to the liquid mercury in the vacuum chamber. Thus, it will be understood that the total amount of mercury to be contained in the gaps of a carrier main body 63 and the force applied to the mercury drops contained in the gaps of a carrier main body 63 to hold them there can be rigorously controlled by controlling those parameters.
  • Such a capability of rigorously controlling the amount of mercury to be contained in the gaps of a carrier main body as well as the force to retain the mercury drops in the gaps of a carrier main body can not by any means be found in a known method of manufacturing mercury carriers.
  • a mercury carrier according to the invention and manufactured by a method according to the invention would never show mercury oozing out from inside onto the surface if the temperature of ambient air violently fluctuates.
  • the carrier main body of a mercury carrier according to the invention is not necessarily made of any of the above listed materials.
  • it may be alternatively made of an inorganic material including glass and various metals.
  • the method of manufacturing porous carrier main bodies is not limited to the one as described above.
  • glass is used as a material for manufacturing carrier main bodies, for instance, sodium chloride is dissolved in molten glass and then the glass is solidified to deposit sodium chloride that has been dissolved in the glass.
  • a piece of a porous material to be used for carrier main bodies is produced when the deposited sodium chloride is removed from the glass.
  • a piece of a porous material may be prepared by forming fine gaps in a homogeneous piece of a material such as glass or metal by means of a machine cutter, laser or an electronic beam.
  • a third embodiment of the present invention as illustrated in Fig. 3 is in fact a fluorescent lamp realized by introducing a mercury carrier 72 according to the invention into an exhaust pipe 4 of a stem 3.
  • the mercury carrier 72 in the fluorescent lamp is heated to discharge mercury into the bulb 1 when the exhaust pipe 4 is pinch-sealed. Since the mercury carrier 72 is housed in an exhaust pipe 4 which is not heated so hot when the lamp is energized, it operates effectively as a getter for catching impurities in the lamp once it has discharged the mercury it used to contain.
  • a mercury carrier 72 to be introduced into an exhaust pipe 4 has preferably a cylindrical form as illustrated in Fig. 8.
  • a mercury carrier according to the invention may be alternatively a spherical mercury carrier 73 comprising small particles as illustrated in Fig. 8.
  • a mercury carrier is realized in such a form, one or more than one mercury carriers may be housed in a single exhaust pipe 4.
  • Figs. 4 and 5 show a fourth embodiment of the mercury vapor discharge lamp of the invention.
  • a mercury carrier 72 is housed in an exhaust pipe and, after discharging the mercury contained in the carrier, both the mercury carrier 72 and the exhaust pipe are totally removed out of the lamp. More specifically, a mercury carrier 72 is introduced into a front end portion of an exhaust pipe 4 and the passage through which the mercury carrier 72 is brought into the exhaust pipe 4 is closed and sealed. At this stage, the mercury carrier 72 is caused to discharge the mercury it contains into the bulb 1 by the heat used for sealing the exhaust pipe. Then, as shown in Fig.
  • the exhaust pipe 4 is pinch-sealed at a position closer to the root of the exhaust pipe than that of the mercury carrier 72 and, thereafter, the front end portion 41 and the mercury carrier 72 housed there are removed from the pipe. Therefore, this embodiment does not have a mercury carrier at all in the bulb when it becomes a finished product.
  • Fig. 10 illustrates how accurately mercury can be discharged into the bulb of a fluorescent lamp by using a mercury carrier according to the invention.
  • the solid line in the graph of Fig. 10 is obtained by plotting the number of fluorescent lamps using a mercury carrier according to the invention for each amount of mercury contained in the lamps which were tested, whereas the broken line indicates the number of fluorescent lamps containing a given amount of mercury charged with mercury by means of a conventional mercury doser, the amount being variable for the tested lamps. It may be needless to say that fluorescent lamps using a mercury carrier according to the invention show little deviation in terms of the amount of mercury contained there.
  • Fig. 11 shows how the flux of light of fluorescent lamps using a mercury carrier according to the invention is maintained for a prolong period of time and hence they have a prolonged service life if compared with lamps charged with mercury by means of a conventional mercury doser.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Manufacture Of Electron Tubes, Discharge Lamp Vessels, Lead-In Wires, And The Like (AREA)
EP19910116800 1990-10-01 1991-10-01 Mercury vapor discharge lamp Withdrawn EP0479259A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP263310/90 1990-10-01
JP2263310A JPH04141940A (ja) 1990-10-01 1990-10-01 水銀蒸気放電灯およびその製造方法

Publications (2)

Publication Number Publication Date
EP0479259A2 true EP0479259A2 (fr) 1992-04-08
EP0479259A3 EP0479259A3 (en) 1992-05-20

Family

ID=17387705

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19910116800 Withdrawn EP0479259A3 (en) 1990-10-01 1991-10-01 Mercury vapor discharge lamp

Country Status (3)

Country Link
EP (1) EP0479259A3 (fr)
JP (1) JPH04141940A (fr)
KR (1) KR940009328B1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0568317A1 (fr) * 1992-04-28 1993-11-03 General Electric Company Introduction d'un liquide dans un article
EP0718869A1 (fr) * 1994-12-20 1996-06-26 Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH Lampe à décharge à basse pression
WO1998053479A1 (fr) * 1997-05-22 1998-11-26 Saes Getters S.P.A. Dispositif et procede pour introduire de petites quantites de mercure dans des lampes fluorescentes
EP1158558A1 (fr) * 2000-05-26 2001-11-28 Ushiodenki Kabushiki Kaisha Méthode de fabrication de lampes à décharge et une lampe à décharge avec des moyens servant a introduire un halogène

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2892665A (en) * 1955-01-31 1959-06-30 Westinghouse Electric Corp Discharge lamp manufacture
DE2203033A1 (de) * 1972-01-22 1973-07-26 Herrmann Gebr Verfahren zur aufnahme von quecksilber durch einen metallbeladenen traeger mit porenradienverteilungskurve
US3825788A (en) * 1972-03-01 1974-07-23 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh High pressure metal vapor discharge lamp with tubular current lead including filler release construction
US4146497A (en) * 1972-12-14 1979-03-27 S.A.E.S. Getters S.P.A. Supported getter
EP0081263A2 (fr) * 1981-12-04 1983-06-15 Koninklijke Philips Electronics N.V. Procédé de fabrication d'une lampe à décharge dans la vapeur de mercure à basse pression
EP0228005A2 (fr) * 1985-12-19 1987-07-08 Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH Elément de stockage pour doser et introduire du mercure liquide dans une lampe à décharge
JPH01220359A (ja) * 1988-02-29 1989-09-04 Toshiba Corp 金属蒸気放電灯およびその製造方法
EP0359724A2 (fr) * 1988-09-12 1990-03-21 SAES GETTERS S.p.A. Cathodes froides pour tubes fluorescents

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2892665A (en) * 1955-01-31 1959-06-30 Westinghouse Electric Corp Discharge lamp manufacture
DE2203033A1 (de) * 1972-01-22 1973-07-26 Herrmann Gebr Verfahren zur aufnahme von quecksilber durch einen metallbeladenen traeger mit porenradienverteilungskurve
US3825788A (en) * 1972-03-01 1974-07-23 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh High pressure metal vapor discharge lamp with tubular current lead including filler release construction
US4146497A (en) * 1972-12-14 1979-03-27 S.A.E.S. Getters S.P.A. Supported getter
EP0081263A2 (fr) * 1981-12-04 1983-06-15 Koninklijke Philips Electronics N.V. Procédé de fabrication d'une lampe à décharge dans la vapeur de mercure à basse pression
EP0228005A2 (fr) * 1985-12-19 1987-07-08 Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH Elément de stockage pour doser et introduire du mercure liquide dans une lampe à décharge
JPH01220359A (ja) * 1988-02-29 1989-09-04 Toshiba Corp 金属蒸気放電灯およびその製造方法
EP0359724A2 (fr) * 1988-09-12 1990-03-21 SAES GETTERS S.p.A. Cathodes froides pour tubes fluorescents

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 13, no. 534 (E-852)(3882) 29 November 1989 & JP-A-1 220 359 ( TOSHIBA CORP ) 4 September 1989 *

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0568317A1 (fr) * 1992-04-28 1993-11-03 General Electric Company Introduction d'un liquide dans un article
EP0718869A1 (fr) * 1994-12-20 1996-06-26 Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH Lampe à décharge à basse pression
US5686788A (en) * 1994-12-20 1997-11-11 Patent-Treuhand-Gesellschaft Fur Elektrische Gluhlampen Mbh Low-pressure discharge lamp with starting amalgam
WO1998053479A1 (fr) * 1997-05-22 1998-11-26 Saes Getters S.P.A. Dispositif et procede pour introduire de petites quantites de mercure dans des lampes fluorescentes
US6680571B1 (en) 1997-05-22 2004-01-20 Saes Getters S.P.A. Device for introducing small amounts of mercury into fluorescent lamps
EP1158558A1 (fr) * 2000-05-26 2001-11-28 Ushiodenki Kabushiki Kaisha Méthode de fabrication de lampes à décharge et une lampe à décharge avec des moyens servant a introduire un halogène
US6814641B2 (en) 2000-05-26 2004-11-09 Ushiodenki Kabushiki Kaisha Method of manufacturing discharge lamps and a discharge lamp with a halogen introduction carrier

Also Published As

Publication number Publication date
JPH04141940A (ja) 1992-05-15
EP0479259A3 (en) 1992-05-20
KR920008828A (ko) 1992-05-28
KR940009328B1 (ko) 1994-10-06

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