[go: up one dir, main page]

EP0592915A1 - Low-pressure discharge lamp and process for producing a low-pressure discharge lamp - Google Patents

Low-pressure discharge lamp and process for producing a low-pressure discharge lamp Download PDF

Info

Publication number
EP0592915A1
EP0592915A1 EP93116008A EP93116008A EP0592915A1 EP 0592915 A1 EP0592915 A1 EP 0592915A1 EP 93116008 A EP93116008 A EP 93116008A EP 93116008 A EP93116008 A EP 93116008A EP 0592915 A1 EP0592915 A1 EP 0592915A1
Authority
EP
European Patent Office
Prior art keywords
barium
low
carbonate
pressure discharge
oxide
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.)
Granted
Application number
EP93116008A
Other languages
German (de)
French (fr)
Other versions
EP0592915B1 (en
Inventor
Christian Harzig
Roland Hoffmann
Erolf Weinhardt
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 EP0592915A1 publication Critical patent/EP0592915A1/en
Application granted granted Critical
Publication of EP0592915B1 publication Critical patent/EP0592915B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/04—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
    • 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
    • H01J9/02—Manufacture of electrodes or electrode systems
    • H01J9/04—Manufacture of electrodes or electrode systems of thermionic cathodes
    • H01J9/042—Manufacture, activation of the emissive part

Definitions

  • the invention relates to a low-pressure discharge lamp according to the preamble of patent claim 1 and a manufacturing method for a low-pressure discharge lamp.
  • the invention relates to an electron emitter for a cold-startable low-pressure discharge lamp with rod-shaped electrode filaments.
  • a lamp corresponding to the preamble of claim 1 is described, for example, in the book "Die Oxidkathode", volume 2, by G. Hermann and S. Wagener, Johann Ambrosius Verlag, Leipzig, 2nd edition (1950) (pages 137-139). It is a fluorescent lamp whose electrode filaments are activated using a mixture of barium and strontium carbonate. According to the authors of this book (pages 25 - 33), a mixture of equal proportions of barium and strontium carbonate provides optimal emission values after activation of the electrode filaments pasted with it. They also state that with an equimolar mixture of barium and strontium carbonate, to which approximately 10% calcium carbonate is added, good emission values are also achieved after activation of the electrodes.
  • the emitter compositions mentioned in the cited book are also suitable for so-called cold-startable low-pressure discharge lamps. These are Low-pressure discharge lamps that are ignited without preheating their electrode filaments.
  • the experiments showed that the electron emission in the low-pressure discharge lamps according to the invention could be increased by adding strontium carbonate to the emitter paste.
  • the switching stability of the lamp according to the invention decreased again and the blackening of the discharge vessel due to sputtering emitter material increased.
  • the limit for a sufficiently good cold start strength is.
  • Particularly favorable results were achieved with a proportion of up to 5 mol% strontium carbonate in the emitter paste made of barium carbonate and with pure barium carbonate as the starting material for the emitter paste, which was set to an average grain size between 3 and 8 ⁇ m during the manufacturing process.
  • the exemplary embodiment is a rod-shaped fluorescent lamp.
  • This lamp has a circular cylindrical discharge vessel with a diameter of approx. 26 mm and a length between 0.6 m and 1.5 m. At the ends of the lamp, two double-wound, rod-shaped electrode filaments made of tungsten are melted in a gas-tight manner. The rod-shaped electrode filaments are arranged transversely to the discharge path.
  • the discharge vessel has a fluorescent coating on its inner wall.
  • the ionizable filling of the fluorescent lamp consists of mercury vapor and a noble gas mixture.
  • the electrode coils are provided with a barium oxide emitter, an excess of metallic barium being generated in the forming process.
  • the discharge tube of the fluorescent lamp is made from a glass tube that has been coated with fluorescent material on its inner wall.
  • the electrode frames are inserted into the ends of the discharge vessel and fused with it.
  • the electrodes are activated at the same time.
  • the lamp is then provided with the ionizable filling, consisting of krypton, argon and mercury, and the pump stem is sealed gas-tight.
  • the two electrode frames each consist of a double-coiled, rod-shaped electrode coil made of tungsten, the power supply lines of which are melted into a glass base.
  • the electrode coils carry an emitter paste made of barium carbonate, which is activated when the Electrodes are converted into barium oxide, which contains small amounts of metallic barium.
  • barium nitrate and a tartrate are obtained in a precipitation system after annealing barium carbonate.
  • the barium carbonate is dried and then ground with butyl acetate and nitrocellulose, so that the average grain size of the barium carbonate powder in the suspension after the grinding process is approximately 5 ⁇ m.
  • the suspension consists of about 80 wt .-% of BaCO3, 18 wt .-% butyl acetate and 2 wt .-% nitrocellulose.
  • the electrode filaments are coated with the latter by immersing them in the emitter paste or suspension.
  • the electrode filaments are heated to a temperature above 800 ° C. for a time of about 10-40 seconds by means of electrical current flow.
  • the binder burns and the barium carbonate is converted into barium oxide.
  • a small part of the barium oxide is reduced to metallic barium during the activation process.
  • the metallic barium increases the electrical conductivity of the semiconducting barium oxide and has a great influence on the electron emission of the barium oxide emitter.
  • the invention is not limited to the exemplary embodiment described above. It is also possible, for example, to use mixed carbonate consisting of barium carbonate and 0 - instead of barium carbonate. Use 5 mol% strontium carbonate to prepare the emitter paste. After activation of the electrode coils, the electron emitter then consists of a mixed oxide which contains barium oxide and strontium oxide and a small part, approx. 0.05 mol%, of metallic barium and metallic strontium. The ratio of barium to strontium oxide in the electron emitter is exactly the same as the ratio of barium to strontium carbonate in the emitter paste.
  • this emitter is of course not limited to the fluorescent lamp of the exemplary embodiment, but rather can be used in many commercially available low-pressure discharge lamps. It is also possible to use this emitter in high pressure sodium discharge lamps. Other solvent / binder systems, for example aqueous suspensions, can also be used.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Discharge Lamp (AREA)

Abstract

The invention relates to a low-pressure discharge lamp and a process for producing such a lamp. The electrode filaments of the low-pressure discharge lamps according to the invention are preferably activated by means of an emitter paste consisting of barium carbonate which contains no further additives. This improves the cold-start resistance of the low-pressure discharge lamps.

Description

Die Erfindung betrifft eine Niederdruckentladungslampe gemäß dem Oberbegriff des Patentanspruchs 1 sowie ein Herstellungsverfahren für eine Niederdruckentladungslampe.
Insbesondere bezieht sich die Erfindung auf einen Elektronenemitter für eine kaltstartfähige Niederdruckentladungslampe mit stabförmigen Elektrodenwendeln.The invention relates to a low-pressure discharge lamp according to the preamble of patent claim 1 and a manufacturing method for a low-pressure discharge lamp.
In particular, the invention relates to an electron emitter for a cold-startable low-pressure discharge lamp with rod-shaped electrode filaments.

Eine dem Oberbegriff des Patentanspruchs 1 entsprechende Lampe ist beispielsweise in dem Buch "Die Oxidkathode", Band 2, von G. Hermann und S. Wagener, Johann Ambrosius Verlag, Leipzig, 2. Auflage (1950) (Seite 137 - 139) beschrieben. Es handelt sich hierbei um eine Leuchtstofflampe, deren Elektrodenwendeln unter Verwendung einer Mischung von Barium- und Strontiumkarbonat aktiviert werden. Laut Aussage der Autoren dieses Buches (Seiten 25 - 33) liefert eine Mischung aus gleichen Anteilen von Barium- und Strontiumkarbonat optimale Emissionswerte nach Aktivierung der damit bepasteten Elektrodenwendeln. Außerdem führen sie aus, daß mit einer äquimolaren Mischung von Barium- und Strontiumkarbonat, der ungefähr 10 % Kalziumkarbonat beigefügt wird, nach Aktivierung der Elektroden ebenfalls gute Emissionswerte erreicht werden. Beim Aktivieren der Elektroden werden die Karbonate in die entsprechenden Metalloxide umgewandelt. Die im zitierten Buch genannten Emitterzusammensetzungen eignen sich auch für sogenannte kaltstartfähige Niederdruckentladungslampen. Das sind Niederdruckentladungslampen, die ohne vorherige Vorheizung ihrer Elektrodenwendeln gezündet werden.A lamp corresponding to the preamble of claim 1 is described, for example, in the book "Die Oxidkathode", volume 2, by G. Hermann and S. Wagener, Johann Ambrosius Verlag, Leipzig, 2nd edition (1950) (pages 137-139). It is a fluorescent lamp whose electrode filaments are activated using a mixture of barium and strontium carbonate. According to the authors of this book (pages 25 - 33), a mixture of equal proportions of barium and strontium carbonate provides optimal emission values after activation of the electrode filaments pasted with it. They also state that with an equimolar mixture of barium and strontium carbonate, to which approximately 10% calcium carbonate is added, good emission values are also achieved after activation of the electrodes. When the electrodes are activated, the carbonates are converted into the corresponding metal oxides. The emitter compositions mentioned in the cited book are also suitable for so-called cold-startable low-pressure discharge lamps. These are Low-pressure discharge lamps that are ignited without preheating their electrode filaments.

Beim Kaltstart von Niederdruckentladungslampen tritt während des Zündvorganges eine extrem hohe Belastung der Elektrodenwendeln auf. In der Glimmphase sind die Elektrodenwendeln einem heftigen Ionenbeschuß ausgesetzt, der zur Aufheizung der Elektroden und zur Ausbildung eines Brennflecks auf den Elektrodenwendeln führt, an dem schließlich der Übergang in die Bogenentladung erfolgt. Der Ionenbeschuß bewirkt allerdings auch eine Schädigung der Elektrodenwendeln durch Absputtern von Elektroden- und Emittermaterial, das sich auf der Innenwand des Entladungsgefäßes niederschlägt und eine unerwünschte Schwärzung der Entladungsgefäßenden verursacht. Lang anhaltende Glimmphasen können so zum vorzeitigen Bruch der Elektrodenwendeln führen und die Lebensdauer der Niederdruckentladungslampe verkürzen.When cold starting low-pressure discharge lamps, an extremely high load on the electrode filaments occurs during the ignition process. In the glow phase, the electrode filaments are subjected to violent ion bombardment, which leads to the heating of the electrodes and to the formation of a focal spot on the electrode filaments, at which point the transition to arc discharge finally takes place. However, the ion bombardment also causes damage to the electrode filaments by sputtering off the electrode and emitter material, which is deposited on the inner wall of the discharge vessel and causes undesired blackening of the discharge vessel ends. Long-lasting glow phases can lead to premature breakage of the electrode filaments and shorten the life of the low-pressure discharge lamp.

Es ist die Aufgabe der Erfindung, eine Niederdruckentladungslampe mit verbesserter Kaltstartfähigkeit sowie ein Herstellungsverfahren für eine derartige Lampe bereitzustellen. Diese Aufgabe wird erfindungsgemäß durch die kennzeichnenden Merkmale des Patentanspruchs 1 bzw. des Verfahrensanspruchs 3 gelöst. Besonders vorteilhafte Ausführungen der Erfindung sind in den Unteransprüchen beschrieben.It is the object of the invention to provide a low-pressure discharge lamp with improved cold start capability and a production method for such a lamp. This object is achieved according to the invention by the characterizing features of patent claim 1 and method claim 3. Particularly advantageous embodiments of the invention are described in the subclaims.

Versuche mit reinem Bariumkarbonat als Emitterpaste für die stabförmigen Elektrodenwendeln von Leuchtstofflampen ergeben überraschenderweise, daß derartige Leuchtstofflampen nach Aktivierung ihrer Elektroden eine gegenüber den mit dem Standardemitter, gemäß des oben zitierten Buchs "Die Oxidkathode", versehenen Leuchtstofflampen eine deutlich verbesserte Kaltstartfestigkeit besitzen. Der reine Bariumoxid-Emitter (mit metallischem Barium dotiert) scheint den Ergebnissen dieser Versuche zufolge besser auf den Elektrodenwendeln aus Wolfram zu haften als der Standardemitter und liefert bereits eine zum Lampenbetrieb ausreichende Elektronenemission, so daß die erfindungsgemäßen Niederdruckentladungslampen weit mehr als 10 000 Schaltungen erlauben, ohne daß eine Schädigung der Elektrodenwendeln und eine nennenswerte Schwärzung des Entladungsgefäßes beobachtet werden konnten. Außerdem zeigten die Experimente, daß bei den erfindungsgemäßen Niederdruckentladungslampen die Elektronenemission durch Zugabe von Strontiumkarbonat zur Emitterpaste erhöht werden konnte. Allerdings nahm dadurch die Schaltfestigkeit der erfindungsgemäßen Lampe wieder ab und die Schwärzung des Entladungsgefäßes durch absputterndes Emittermaterial zu. Bei einem Anteil von etwa 20 Mol.-% Strontiumkarbonat in der Emitterpaste aus Bariumkarbonat liegt die Grenze für eine ausreichend gute Kaltstartfestigkeit. Besonders günstige Resultate wurden mit einem Anteil von bis zu 5 Mol.% Strontiumkarbonat in der Emitterpaste aus Bariumkarbonat und mit reinem Bariumkarbonat als Ausgangsmaterial für die Emitterpaste erzielt, das beim Herstellungsprozeß auf eine mittlere Korngröße zwischen 3 und 8 µm eingestellt wurde.Experiments with pure barium carbonate as an emitter paste for the rod-shaped electrode filaments of fluorescent lamps surprisingly show that after activation of their electrodes, such fluorescent lamps are compared to those with the standard emitter according to Book cited above "Die Oxidkathode", provided fluorescent lamps have a significantly improved cold start resistance. According to the results of these tests, the pure barium oxide emitter (doped with metallic barium) appears to adhere better to the tungsten electrode filaments than the standard emitter and already provides sufficient electron emission for lamp operation, so that the low-pressure discharge lamps according to the invention permit far more than 10,000 switching operations. without damage to the electrode filaments and significant blackening of the discharge vessel being observed. In addition, the experiments showed that the electron emission in the low-pressure discharge lamps according to the invention could be increased by adding strontium carbonate to the emitter paste. However, the switching stability of the lamp according to the invention decreased again and the blackening of the discharge vessel due to sputtering emitter material increased. With a proportion of about 20 mol% strontium carbonate in the barium carbonate emitter paste, the limit for a sufficiently good cold start strength is. Particularly favorable results were achieved with a proportion of up to 5 mol% strontium carbonate in the emitter paste made of barium carbonate and with pure barium carbonate as the starting material for the emitter paste, which was set to an average grain size between 3 and 8 µm during the manufacturing process.

Die Erfindung wird nachstehend anhand eines besonders bevorzugten Ausführungsbeispiels näher erläutert.The invention is explained below with reference to a particularly preferred embodiment.

Bei dem Ausführungsbeispiel handelt es sich um eine stabförmige Leuchtstofflampe. Diese Lampe besitzt ein kreiszylindrisches Entladungsgefäß mit einem Durchmesser von ca. 26 mm und einer Länge zwischen 0,6 m und 1,5 m. An den Enden der Lampe sind zwei doppelt gewendelte, stabförmige Elektrodenwendeln aus Wolfram gasdicht eingeschmolzen. Die stabförmigen Elektrodenwendeln sind quer zur Entladungsstrecke angeordnet. Das Entladungsgefäß trägt auf seiner Innenwand eine Leuchtstoffbeschichtung. Die ionisierbare Füllung der Leuchtstofflampe besteht aus Quecksilberdampf und einem Edelgasgemisch. Die Elektrodenwendeln sind mit einem Bariumoxidemitter versehen, wobei beim Formierprozeß ein Überschuß an metallischem Barium erzeugt wird.The exemplary embodiment is a rod-shaped fluorescent lamp. This lamp has a circular cylindrical discharge vessel with a diameter of approx. 26 mm and a length between 0.6 m and 1.5 m. At the ends of the lamp, two double-wound, rod-shaped electrode filaments made of tungsten are melted in a gas-tight manner. The rod-shaped electrode filaments are arranged transversely to the discharge path. The discharge vessel has a fluorescent coating on its inner wall. The ionizable filling of the fluorescent lamp consists of mercury vapor and a noble gas mixture. The electrode coils are provided with a barium oxide emitter, an excess of metallic barium being generated in the forming process.

Die Herstellung einer erfindungsgemäßen Niederdruckentladungslampe und insbesondere die Präparation des Elektronenemitters wird nun anhand des Ausführungsbeispiels näher beschrieben. Das Entladungsgefäß der Leuchtstofflampe wird aus einem Glasrohr hergestellt, das auf seiner Innenwand mit Leuchtstoff beschlämmt wurde. Nach dem Ausheizen der Bindemittel werden die Elektrodengestelle in die Enden des Entladungsgefäßes eingesetzt und mit diesem verschmolzen. Während des folgenden Pumpprozesses, bei dem Verunreinigungen aus dem Entladungsgefäß entfernt werden, werden gleichzeitig die Elektroden aktiviert. Anschließend wird die Lampe mit der ionisierbaren Füllung, bestehend aus Krypton, Argon und Quecksilber, versehen und der Pumpstengel gasdicht verschlossen. Die beiden Elektrodengestelle bestehen jeweils aus einer doppelt gewendelten, stabförmigen Elektrodenwendel aus Wolfram, deren Stromzuführungen in einem Glasfuß eingeschmolzen sind. Die Elektrodenwendeln tragen eine Emitterpaste aus Bariumkarbonat, das beim Aktivieren der Elektroden in Bariumoxid, welches geringe Mengen an metallischem Barium enthält, umgewandelt wird.The production of a low-pressure discharge lamp according to the invention and in particular the preparation of the electron emitter will now be described in more detail using the exemplary embodiment. The discharge tube of the fluorescent lamp is made from a glass tube that has been coated with fluorescent material on its inner wall. After the binder has been baked out, the electrode frames are inserted into the ends of the discharge vessel and fused with it. During the following pumping process, in which impurities are removed from the discharge vessel, the electrodes are activated at the same time. The lamp is then provided with the ionizable filling, consisting of krypton, argon and mercury, and the pump stem is sealed gas-tight. The two electrode frames each consist of a double-coiled, rod-shaped electrode coil made of tungsten, the power supply lines of which are melted into a glass base. The electrode coils carry an emitter paste made of barium carbonate, which is activated when the Electrodes are converted into barium oxide, which contains small amounts of metallic barium.

Zur Herstellung des Elektronenemitters wird in einer Fällungsanlage aus den Ausgangsmaterialien Bariumnitrat und einem Tartrat, vorzugsweise Kalium-Natrium-Tartrat, nach Verglühung Bariumkarbonat gewonnen. Das Bariumkarbonat wird getrocknet und anschließend mit Butylacetat und Nitrocellulose vermahlen, so daß die mittlere Korngröße des Bariumkarbonatpulvers in der Suspension nach dem Mahlprozeß ungefähr 5 µm beträgt. Die Suspension besteht zu ca. 80 Gew.-% aus BaCO₃, 18 Gew.-% Butylacetat und 2 Gew.-% Nitrocellulose. Vor dem Einschmelzen der Elektrodengestelle in das Entladungsgefäß werden die Elektrodenwendeln durch Eintauchen in die Emitterpaste bzw. Suspension mit dieser beschichtet.To produce the electron emitter, barium nitrate and a tartrate, preferably potassium sodium tartrate, are obtained in a precipitation system after annealing barium carbonate. The barium carbonate is dried and then ground with butyl acetate and nitrocellulose, so that the average grain size of the barium carbonate powder in the suspension after the grinding process is approximately 5 μm. The suspension consists of about 80 wt .-% of BaCO₃, 18 wt .-% butyl acetate and 2 wt .-% nitrocellulose. Before the electrode frames are melted into the discharge vessel, the electrode filaments are coated with the latter by immersing them in the emitter paste or suspension.

Zum Aktivieren der mit der Emitterpaste versehenen Elektrodenwendeln werden die Elektrodenwendeln mittels elektrischem Stromfluß für eine Zeit von etwa 10 - 40 Sekunden auf eine Temperatur oberhalb von 800°C erhitzt. Dabei verbrennt der Binder und das Bariumkarbonat wird in Bariumoxid umgewandelt. Außerdem wird beim Aktivierungsprozeß ein geringer Teil des Bariumoxids zu metallischem Barium reduziert. Das metallische Barium erhöht die elektrische Leitfähigkeit des halbleitenden Bariumoxids und hat großen Einfluß auf die Elektronenemission des Bariumoxidemitters.In order to activate the electrode filaments provided with the emitter paste, the electrode filaments are heated to a temperature above 800 ° C. for a time of about 10-40 seconds by means of electrical current flow. The binder burns and the barium carbonate is converted into barium oxide. In addition, a small part of the barium oxide is reduced to metallic barium during the activation process. The metallic barium increases the electrical conductivity of the semiconducting barium oxide and has a great influence on the electron emission of the barium oxide emitter.

Die Erfindung beschränkt sich nicht auf das oben beschriebene Ausführungsbeispiel. Es ist beispielsweise auch möglich, anstelle von Bariumkarbonat auch ein Mischkarbonat, bestehend aus Bariumkarbonat und 0 - 5 Mol.-% Strontiumkarbonat zum Ansetzen der Emitterpaste zu verwenden. Der Elektronenemitter besteht dann, nach Aktivierung der Elektrodenwendeln, aus einem Mischoxid, das Bariumoxid und Strontiumoxid enthält und einem geringen Teil, ca. 0,05 Mol.-%, von metallischem Barium sowie metallischem Strontium. Das Verhältnis von Barium- zu Strontiumoxid ist im Elektronenemitter genau so groß wie das Verhältnis von Barium- zu Strontiumkarbonat in der Emitterpaste. Ferner ist die Anwendung dieses Emitters natürlich nicht auf die Leuchtstofflampe des Ausführungsbeispiels beschränkt, sondern kann vielmehr in vielen handelsüblichen Niederdruckentladungslampen benutzt werden. Es ist auch möglich, diesen Emitter in Natriumhochdruckentladungslampen zu verwenden. Ebenso können auch andere Lösungsmittel/Bindersysteme, beispielsweise wässrige Suspensionen, verwendet werden.The invention is not limited to the exemplary embodiment described above. It is also possible, for example, to use mixed carbonate consisting of barium carbonate and 0 - instead of barium carbonate. Use 5 mol% strontium carbonate to prepare the emitter paste. After activation of the electrode coils, the electron emitter then consists of a mixed oxide which contains barium oxide and strontium oxide and a small part, approx. 0.05 mol%, of metallic barium and metallic strontium. The ratio of barium to strontium oxide in the electron emitter is exactly the same as the ratio of barium to strontium carbonate in the emitter paste. Furthermore, the use of this emitter is of course not limited to the fluorescent lamp of the exemplary embodiment, but rather can be used in many commercially available low-pressure discharge lamps. It is also possible to use this emitter in high pressure sodium discharge lamps. Other solvent / binder systems, for example aqueous suspensions, can also be used.

Claims (4)

Niederdruckentladungslampe mit einem Entladungsgefäß, das zwei darin angeordnete Elektroden sowie eine gasdicht darin eingeschlossene ionisierbare Füllung enthält, wobei die Elektroden als doppelt gewendelte, stabförmige, quer zur Entladungsstrecke angeordnete und mit einem Elektronenemitter versehene Wolframwendeln ausgeführt sind, dadurch gekennzeichnet, daß der Elektronenemitter aus Bariumoxid, das einen geringen Anteil an metallischen Barium aufweist, besteht.Low-pressure discharge lamp with a discharge vessel, which contains two electrodes arranged therein and an ionizable filling enclosed gas-tight therein, the electrodes being designed as double-coiled, rod-shaped tungsten filaments arranged transversely to the discharge path and provided with an electron emitter, characterized in that the electron emitter is made of barium oxide, which contains a small amount of metallic barium. Niederdruckentladungslampe nach Anspruch 1, dadurch gekennzeichnet, daß der Elektronenemitter aus Bariumoxid und aus einem Anteil von maximal 20 Mol.-% Strontiumoxid besteht, wobei die Oxide einen geringen Anteil an metallischen Barium und/oder Strontium aufweisen.Low-pressure discharge lamp according to Claim 1, characterized in that the electron emitter consists of barium oxide and a proportion of at most 20 mol% strontium oxide, the oxides having a small proportion of metallic barium and / or strontium. Niederdruckentladungslampe nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß der Elektronenemitter aus Bariumoxid und aus einem Anteil von bis zu 5 Mol.-% Strontiumoxid besteht, wobei die Oxide einen geringen Anteil an metallischen Barium und/oder Strontium aufweisen.Low-pressure discharge lamp according to Claim 1 or 2, characterized in that the electron emitter consists of barium oxide and a proportion of up to 5 mol% of strontium oxide, the oxides having a small proportion of metallic barium and / or strontium. Verfahren zur Herstellung einer Niederdruckentladungslampe nach den Ansprüchen 1 oder 2, dadurch gekennzeichnet, daß das Verfahren zur Herstellung der mit dem Elektronenemitter versehenen Elektrodenwendeln folgende Fertigungsschritte enthält: - Herstellen von Bariumkarbonat, gegebenenfalls mit einem Anteil von 0 - 20 Mol.-% Strontiumkarbonat, in einer Fällungsanlage aus den Ausgangsprodukten Bariumnitrat und einem Tartrat, sowie gegebenenfalls Strontiumnitrat, - Trocknen des Bariumkarbonats bzw. des Mischkarbonats und anschließende Mahlung, - Ansetzen einer Emitterpaste bestehend aus ca. 80 Teilen Bariumkarbonat bzw. Mischkarbonat und 18 Teilen Butylacetat sowie 2 Teilen Nitrocellulose, - Bepasten der Elektrodenwendeln mit der Emitterpaste, - Anschmelzen der Elektrodengestelle an das Entladungsgefäß, - Abpumpen des Entladungsgefäßes und Aktivieren der Elektrodenwendeln, wobei der Aktivierungsprozeß folgende Schritte umfaßt: - Ausbrennen des Binders, - Umwandlung des Karbonats in das Oxid, - Anreicherung des Oxids mit dem metallischen Bestandteil durch Sauerstoffentzug, - Einbringen der ionisierbaren Füllung und gasdichtes Verschließen des Entladungsgefäßes. A process for producing a low-pressure discharge lamp according to claims 1 or 2, characterized in that the process for producing the electrode filaments provided with the electron emitter contains the following production steps: - Manufacture of barium carbonate, if necessary with a share of 0 - 20 mol% strontium carbonate, in a precipitation plant from the starting products barium nitrate and a tartrate, and optionally strontium nitrate, Drying the barium carbonate or the mixed carbonate and subsequent grinding, Preparation of an emitter paste consisting of approx. 80 parts barium carbonate or mixed carbonate and 18 parts butyl acetate and 2 parts nitrocellulose, - pasting the electrode coils with the emitter paste, Melting the electrode racks onto the discharge vessel, - Pumping off the discharge vessel and activating the electrode filaments, the activation process comprising the following steps: - burning out the binder, Conversion of the carbonate to the oxide, Enrichment of the oxide with the metallic component by oxygen deprivation, - Introducing the ionizable filling and gas-tight sealing of the discharge vessel.
EP93116008A 1992-10-15 1993-10-04 Low-pressure discharge lamp and process for producing a low-pressure discharge lamp Expired - Lifetime EP0592915B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4234843 1992-10-15
DE4234843A DE4234843A1 (en) 1992-10-15 1992-10-15 Low pressure discharge lamp and manufacturing method for a low pressure discharge lamp

Publications (2)

Publication Number Publication Date
EP0592915A1 true EP0592915A1 (en) 1994-04-20
EP0592915B1 EP0592915B1 (en) 1995-12-27

Family

ID=6470577

Family Applications (1)

Application Number Title Priority Date Filing Date
EP93116008A Expired - Lifetime EP0592915B1 (en) 1992-10-15 1993-10-04 Low-pressure discharge lamp and process for producing a low-pressure discharge lamp

Country Status (6)

Country Link
US (1) US5614784A (en)
EP (1) EP0592915B1 (en)
JP (1) JPH06203793A (en)
KR (1) KR100275168B1 (en)
CA (1) CA2107942A1 (en)
DE (2) DE4234843A1 (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0946968B1 (en) * 1997-10-22 2004-05-06 Koninklijke Philips Electronics N.V. Low-pressure discharge lamp and compact fluorescent lamp
US6384534B1 (en) 1999-12-17 2002-05-07 General Electric Company Electrode material for fluorescent lamps
US6713950B2 (en) 2001-08-22 2004-03-30 General Electric Company Low volatility slurry for emission mix powder
DE10242245A1 (en) * 2002-09-12 2004-03-25 Philips Intellectual Property & Standards Gmbh Low pressure discharge lamp comprises gas discharge vessel containing noble gas filling, electrodes and devices for producing and maintaining a low pressure gas discharge, and an electron emitter material
JP2009508320A (en) * 2005-09-14 2009-02-26 リッテルフューズ，インコーポレイティド Surge arrester with gas, activation compound, ignition stripe and method thereof
KR100867411B1 (en) * 2007-12-29 2008-11-06 (주)화인텍콤포지트 manhole
CN107062027A (en) * 2016-12-08 2017-08-18 安徽世林照明股份有限公司 A kind of packaging technology of fluorescent-lamp tube

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB967273A (en) * 1959-12-17 1964-08-19 Gen Electric Improvements in cathodes and in the method of their manufacture
JPS5460777A (en) * 1977-10-21 1979-05-16 Mitsubishi Electric Corp Fluorescent lamp
GB2095893A (en) * 1981-03-06 1982-10-06 Hamamatsu Tv Co Ltd Cathode for a gas discharge tube

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3798492A (en) * 1971-05-17 1974-03-19 Itt Emissive electrode
US3719856A (en) * 1971-05-19 1973-03-06 O Koppius Impregnants for dispenser cathodes
US3758809A (en) * 1971-06-07 1973-09-11 Itt Emissive fused pellet electrode
US3842469A (en) * 1971-11-19 1974-10-22 Itt Method of activating electron emissive electrodes
US3766423A (en) * 1971-12-03 1973-10-16 Itt Integral emissive electrode
US3837909A (en) * 1972-07-27 1974-09-24 Itt Coated coil emissive electrode
US4031426A (en) * 1974-07-10 1977-06-21 International Telephone And Telegraph Corporation Emissive coating for electrodes
US3969279A (en) * 1974-08-13 1976-07-13 International Telephone And Telegraph Corporation Method of treating electron emissive cathodes
DE2951741C2 (en) * 1978-12-29 1984-05-30 Mitsubishi Denki K.K., Tokio/Tokyo Electrode for a discharge lamp
US4897574A (en) * 1986-10-07 1990-01-30 Mitsubishi Denki Kabushiki Kaisha Hot cathode in wire form
US4836816A (en) * 1988-05-06 1989-06-06 Gte Products Corporation Method of treating tungsten cathodes
FR2658360B1 (en) * 1990-02-09 1996-08-14 Thomson Tubes Electroniques PROCESS FOR MANUFACTURING AN IMPREGNATED CATHODE AND CATHODE OBTAINED BY THIS PROCESS.
NL9002771A (en) * 1990-12-17 1992-07-16 Philips Nv LOW-PRESSURE MERCURY DISCHARGE LAMP.
JPH05205696A (en) * 1991-11-25 1993-08-13 Matsushita Electric Works Ltd Electrode for discharge lamp and manufacture of the same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB967273A (en) * 1959-12-17 1964-08-19 Gen Electric Improvements in cathodes and in the method of their manufacture
JPS5460777A (en) * 1977-10-21 1979-05-16 Mitsubishi Electric Corp Fluorescent lamp
GB2095893A (en) * 1981-03-06 1982-10-06 Hamamatsu Tv Co Ltd Cathode for a gas discharge tube

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
G. HERRMANN & S. WAGENER: "The oxide-coated cathode", 1951, CHAPMAN & HALL LTD., LONDON *
PATENT ABSTRACTS OF JAPAN vol. 3, no. 84 (M - 066) 20 July 1979 (1979-07-20) *

Also Published As

Publication number Publication date
JPH06203793A (en) 1994-07-22
CA2107942A1 (en) 1994-04-16
EP0592915B1 (en) 1995-12-27
US5614784A (en) 1997-03-25
DE4234843A1 (en) 1994-04-21
DE59301249D1 (en) 1996-02-08
KR100275168B1 (en) 2001-01-15
KR940010169A (en) 1994-05-24

Similar Documents

Publication Publication Date Title
EP0652586B1 (en) Metal-halide discharge lamp with a ceramic discharge tube and method of making the same
DE69323026T2 (en) High pressure discharge lamp
DE10291427B4 (en) Metal halide lamp for a motor vehicle headlight
DE2161173C3 (en) Oxide electrode for high-power electric gas discharge lamps
DE68911954T2 (en) Electric lamp.
DE69731374T2 (en) LOW PRESSURE DISCHARGE LAMP
DE2746671A1 (en) ELECTRIC HIGH PRESSURE DISCHARGE LAMP
DE69604362T2 (en) ELECTRODELESS LOW PRESSURE DISCHARGE LAMP
DE3038993A1 (en) METAL STEAM DISCHARGE LAMP
DE69405181T2 (en) High pressure discharge lamp
EP0592915B1 (en) Low-pressure discharge lamp and process for producing a low-pressure discharge lamp
DE1911985A1 (en) Arc discharge lamp with metal halide additive
DE967713C (en) Emission electrode for electrical discharge tubes and process for the production of this electrode
DE69105103T2 (en) Low pressure discharge lamp.
DE2422576C3 (en) Mercury vapor lamp
DE19957420A1 (en) Gas discharge lamp with an oxide emitter electrode
DE69526657T2 (en) Low-pressure discharge lamp
DE19616408A1 (en) Electrode for discharge lamps
DE2655726A1 (en) ELECTRICALLY CONDUCTIVE METAL CERAMICS AND THE PROCESS FOR THEIR PRODUCTION
DE69824824T2 (en) GASKET OF LAMP PISTON
DE69608261T2 (en) LOW PRESSURE DISCHARGE LAMP
DE2845283A1 (en) HIGH INTENSITY DISCHARGE LAMP
EP1104005B1 (en) Gas discharge lamp having an oxide emitter electrode
DE2845333A1 (en) HIGHLY INTENSIVE DISCHARGE LAMPS
DE2939871C2 (en) High pressure sodium vapor discharge lamp

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: A1

Designated state(s): DE FR GB IT

17P Request for examination filed

Effective date: 19940504

17Q First examination report despatched

Effective date: 19940609

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT

REF Corresponds to:

Ref document number: 59301249

Country of ref document: DE

Date of ref document: 19960208

ITF It: translation for a ep patent filed
GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19960304

ET Fr: translation filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19961025

Year of fee payment: 4

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

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

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19971004

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19971031

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19971004

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20051004

REG Reference to a national code

Ref country code: DE

Ref legal event code: R081

Ref document number: 59301249

Country of ref document: DE

Owner name: OSRAM GMBH, DE

Free format text: FORMER OWNER: OSRAM GESELLSCHAFT MIT BESCHRAENKTER HAFTUNG, 81543 MUENCHEN, DE

Effective date: 20111130

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20121023

Year of fee payment: 20

REG Reference to a national code

Ref country code: DE

Ref legal event code: R081

Ref document number: 59301249

Country of ref document: DE

Owner name: OSRAM GMBH, DE

Free format text: FORMER OWNER: OSRAM AG, 81543 MUENCHEN, DE

Effective date: 20130205

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 59301249

Country of ref document: DE

REG Reference to a national code

Ref country code: DE

Ref legal event code: R081

Ref document number: 59301249

Country of ref document: DE

Owner name: OSRAM GMBH, DE

Free format text: FORMER OWNER: OSRAM GMBH, 81543 MUENCHEN, DE

Effective date: 20130822

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20131005