EP0448172A1 - Hochdruckentladungslampe - Google Patents
Hochdruckentladungslampe Download PDFInfo
- Publication number
- EP0448172A1 EP0448172A1 EP91200610A EP91200610A EP0448172A1 EP 0448172 A1 EP0448172 A1 EP 0448172A1 EP 91200610 A EP91200610 A EP 91200610A EP 91200610 A EP91200610 A EP 91200610A EP 0448172 A1 EP0448172 A1 EP 0448172A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- lamp
- aluminium nitride
- discharge lamp
- pressure
- throughs
- 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- Withdrawn
Links
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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
- H01J61/30—Vessels; Containers
- H01J61/302—Vessels; Containers characterised by the material of 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
- H01J61/36—Seals between parts of vessels; Seals for leading-in conductors; Leading-in conductors
- H01J61/366—Seals for leading-in conductors
Definitions
- the invention relates to a high-pressure discharge lamp comprising a closed discharge vessel of translucent sintered aluminium nitride in which electrodes are arranged between which the discharge is maintained during lamp operation, the electrodes being connected each to a respective current-lead throughs passed to the exterior through the discharge vessel wall.
- a high-pressure discharge lamp of the kind described is known from the Japanese Patent Application published under number 60-193254 (1985).
- the known lamp is a high-pressure sodium vapour discharge lamp which contains sodium, mercury and xenon and which has current lead-throughs made of niobium.
- the aluminium nitride has good light transmission characteristics and a good heat conduction so that the discharge vessel assumes an even temperature (substantially isothermal) during operation and also has a great resistance to thermal shocks.
- a disadvantage of this known lamp is that the niobium current lead-throughs become brittle during operation, so that the electrodes can easily break off the current lead-throughs. It has been found that this embrittlement is caused by a chemical reaction of the niobium with nitrogen originating from the aluminium nitride of which the discharge vessel wall is made.
- a further disadvantage of the known lamp is that leaks easily occur at the area of the current lead-throughs. It has been found that these leaks are caused by the relatively great difference in thermal coefficient of expansion between the niobium current lead-throughs and the aluminium nitride of the discharge vessel (the coefficient of expansion of AlN is no more than approximately 60 % of that of the Nb). As a result, mechanical stresses occur during lamp operation, giving rise to the said lamp leaks.
- the invention has for its object to provide an improved high pressure discharge lamp in which the disadvantages referred to are obviated.
- a high-pressure discharge lamp of the kind described in the opening paragraph is characterized in that the current lead-throughs consist at least substantially of molybdenum and/or tungsten.
- a high-pressure discharge lamp with a long operational life is thus obtained in which both the embrittlement of the current lead-throughs and the occurrence of leaks at the area of the current lead-throughs are prevented.
- the molybdenum or tungsten substantially does not react with the nitrogen of the aluminium nitride and as a result retains its mechanical strength, while its coefficient of expansion is similar to that of the aluminium nitride.
- the lamp is constructed as a high-pressure sodium vapour discharge lamp of which the aluminium nitride discharge vessel contains sodium, mercury and rare gas.
- a high-pressure discharge lamp according to the invention is characterized in that the lamp is constructed as a high-pressure mercury vapour discharge lamp of which the aluminium nitride discharge vessel contains, besides mercury and rare gas, one or several halides.
- halides are sodium iodide, thallium iodide, indium iodide, cadmium iodide, aluminium iodide, lanthanum iodide and yttrium iodide.
- a further favourable embodiment of a high-pressure discharge lamp according to the invention is characterized in that the aluminium nitride discharge vessel is accommodated in a glass outer bulb which is provided with two electrical contacts, the current lead-throughs being each connected to a respective electrical contact.
- the outer bulb may, for example, be provided with a lamp cap with two electrical contacts at one end. It is alternatively possible to use a, for example tubular, outer bulb which has an electrical contact at each of its two ends.
- the outer bulb may be evacuated.
- the outer bulb is filled with an inert gas, by which evaporation of the aluminium nitride and the resulting deposition of an aluminium layer on the outer bulb are counteracted, especially in the case of a discharge vessel having a high operating temperature.
- the inert gas also provides cooling of the discharge vessel, so that the latter does not exceed the maximum admissible operating temperature, and high wall loads (W/m2) of the discharge vessel are made possible (compact discharge vessel).
- the inert gas preferably is nitrogen under an operating pressure of 0.5 to 1 bar.
- the lamp according to Fig. 1 comprises a discharge vessel 1 which is closed in a vacuum-tight manner and is made of translucent sintered aluminium nitride, in which are present sodium, mercury, and a rare gas, for example xenon.
- a discharge vessel 1 which is closed in a vacuum-tight manner and is made of translucent sintered aluminium nitride, in which are present sodium, mercury, and a rare gas, for example xenon.
- the electrode 2 is connected to a current lead-through 4 which consists of a tungsten pin which is passed through the wall of the discharge vessel to the exterior.
- the electrode 3 is connected to a current lead-through 5 which also consists of a tungsten pin which is passed through the wall of the discharge vessel 1 to the exterior.
- the tungsten pins 4 and 5 are sintered directly in the aluminium nitride wall of the discharge vessel 1, they do not become brittle under the influence of nitrogen originating from the aluminium nitride, and they have a coefficient of expansion which substantially corresponds to the coefficient of expansion of the aluminium nitride, so that mechanical stresses, which could lead to lamp leaks, are prevented during lamp operation.
- the tungsten pins also have a good chemical resistance to the sodium and the mercury of the discharge. If so desired, current lead-throughs of molybdenum instead of tunsten may be used in this lamp.
- the current lead-throughs are sintered directly into the wall of the aluminium nitride discharge vessel in this case, it is alternatively possible to use a melting glass as a connecting material.
- the aluminium nitride discharge vessel 1 may be accommodated in an outer bulb which is provided with a lamp cap having two electrical contacts, or provided with two electrical contacts situated at opposite ends (not shown in the drawing).
- an outer bulb may be filled with an inert gas, such as nitrogen.
- the lamp of Fig. 2 has a discharge vessel 11 which is closed in a vacuum-tight manner and is made of translucent sintered aluminium nitride in which mercury, a rare gas such as argon, and a few halides such as sodium iodide, thallium iodide and indium iodide are present.
- a discharge vessel 11 In the discharge vessel 11 are arranged electrodes 12 and 13 made of tungsten between which the discharge is maintained during lamp operation.
- the electrode 12 is connected to a current lead-through 14 which consists of a molybdenum tube and which is passed to the exterior through the wall of the discharge vessel.
- the electrode 13 is connected to a current lead-through 15 which also consists of a molybdenum tube which is passed to the exterior through the wall of the discharge vessel.
- the current lead-through 14 is connected to an aluminium nitride plug 17 by means of a connecting glass 16 which is resistant to the filling present in the discharge vessel 11.
- the current lead-through 15 is fastened to an aluminium nitride plug 18 by means of connecting glass 16.
- the plugs 17 and 18 are sintered in a vacuum-tight manner to the wall of the discharge vessel 11.
- the discharge vessel 11 is accommodated in a glass outer bulb 19 which is provided with a lamp cap 20 which has two electrical contacts (bottom contact and side contact in usual fashion).
- Current lead-through 14 is connected to one of the two electrical contacts of the lamp cap 20 through a current conductor 21.
- Current lead-through 15 is connected to the other electrical contact of the lamp cap 20 through current conductor 22.
- the outer bulb 19 is filled with nitrogen under an operating pressure of, for example, 1 bar.
- the molybdenum current lead-throughs 14 and 15 do not become brittle under the influence of the nitrogen originating from aluminium nitride of the discharge vessel or from the nitrogen present in the outer bulb.
- the molybdenum current lead-throughs 14 and 15 have a coefficient of expansion which corresponds substantially to that of the aluminium nitride discharge vessel 11 and of the aluminium nitride plugs 17 and 18, so that mechanical stresses and the concomitant lamp leaks are prevented.
- the molybdenum current lead-throughs 14 and 15 furthermore have, as does the aluminium nitride, a good chemical resistance to the mercury and the halides in the discharge vessel 11. If so desired, the current lead-throughs 14 and 15 in this lamp may be made of tungsten instead of molybdenum.
- the nitrogen filling of the outer bulb 19 ensures that evaporation of aluminium nitride from the wall of the discharge vessel 11 is counteracted during lamp operation, so that no aluminium film will be formed on the outer bulb 19.
Landscapes
- Vessels And Coating Films For Discharge Lamps (AREA)
- Common Detailed Techniques For Electron Tubes Or Discharge Tubes (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL9000687 | 1990-03-23 | ||
NL9000687 | 1990-03-23 |
Publications (1)
Publication Number | Publication Date |
---|---|
EP0448172A1 true EP0448172A1 (de) | 1991-09-25 |
Family
ID=19856802
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP91200610A Withdrawn EP0448172A1 (de) | 1990-03-23 | 1991-03-20 | Hochdruckentladungslampe |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0448172A1 (de) |
JP (1) | JPH04223037A (de) |
CN (1) | CN1055257A (de) |
HU (1) | HUT57468A (de) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1903598A2 (de) * | 2006-09-22 | 2008-03-26 | Toshiba Lighting & Technology Corporation | Hochdruckentladungslampe, Betriebsvorrichtung für eine Hochdruckentladungslampe und Leuchte |
US7960915B2 (en) | 2005-12-16 | 2011-06-14 | Tokuyama Corporation | Cement for bonding an aluminum nitride arc tube body to a molybdenum electrode support, articles made therefrom, and methods for making same |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004528694A (ja) * | 2001-05-08 | 2004-09-16 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | セラミックメタルハライドランプ |
EP2553711B1 (de) * | 2010-04-02 | 2015-09-02 | Koninklijke Philips N.V. | Durchführung einer keramik-metallhalogenidlampe mit einem iridiumdraht |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3234421A (en) * | 1961-01-23 | 1966-02-08 | Gen Electric | Metallic halide electric discharge lamps |
JPS60193254A (ja) * | 1984-03-15 | 1985-10-01 | Tokuyama Soda Co Ltd | 発光管 |
EP0178700A1 (de) * | 1984-09-19 | 1986-04-23 | Koninklijke Philips Electronics N.V. | Elektrische Lampe und Glaszusammensetzung |
EP0371315A2 (de) * | 1988-12-01 | 1990-06-06 | Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH | Entladungsgefäss für eine Hochdruckentladungslampe und Verfahren zu dessen Herstellung |
-
1991
- 1991-03-20 EP EP91200610A patent/EP0448172A1/de not_active Withdrawn
- 1991-03-20 JP JP3080625A patent/JPH04223037A/ja active Pending
- 1991-03-20 HU HU91991A patent/HUT57468A/hu unknown
- 1991-03-20 CN CN 91101849 patent/CN1055257A/zh active Pending
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3234421A (en) * | 1961-01-23 | 1966-02-08 | Gen Electric | Metallic halide electric discharge lamps |
JPS60193254A (ja) * | 1984-03-15 | 1985-10-01 | Tokuyama Soda Co Ltd | 発光管 |
EP0178700A1 (de) * | 1984-09-19 | 1986-04-23 | Koninklijke Philips Electronics N.V. | Elektrische Lampe und Glaszusammensetzung |
EP0371315A2 (de) * | 1988-12-01 | 1990-06-06 | Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH | Entladungsgefäss für eine Hochdruckentladungslampe und Verfahren zu dessen Herstellung |
Non-Patent Citations (1)
Title |
---|
PATENT ABSTRACTS OF JAPAN vol. 10, no. 35 (E-380)(2092) 12 February 1986, & JP-A-60 193254 (TOKUYAMA SODA) 01 October 1985, * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7960915B2 (en) | 2005-12-16 | 2011-06-14 | Tokuyama Corporation | Cement for bonding an aluminum nitride arc tube body to a molybdenum electrode support, articles made therefrom, and methods for making same |
EP1903598A2 (de) * | 2006-09-22 | 2008-03-26 | Toshiba Lighting & Technology Corporation | Hochdruckentladungslampe, Betriebsvorrichtung für eine Hochdruckentladungslampe und Leuchte |
EP1903598A3 (de) * | 2006-09-22 | 2010-01-06 | Toshiba Lighting & Technology Corporation | Hochdruckentladungslampe, Betriebsvorrichtung für eine Hochdruckentladungslampe und Leuchte |
Also Published As
Publication number | Publication date |
---|---|
CN1055257A (zh) | 1991-10-09 |
HUT57468A (en) | 1991-11-28 |
JPH04223037A (ja) | 1992-08-12 |
HU910919D0 (en) | 1991-10-28 |
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Legal Events
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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 |
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AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): BE DE ES FR GB IT NL |
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Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
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18D | Application deemed to be withdrawn |
Effective date: 19920326 |