EP0520248B1 - Electric lamp - Google Patents

Electric lamp Download PDF

Info

Publication number
EP0520248B1
EP0520248B1 EP92109848A EP92109848A EP0520248B1 EP 0520248 B1 EP0520248 B1 EP 0520248B1 EP 92109848 A EP92109848 A EP 92109848A EP 92109848 A EP92109848 A EP 92109848A EP 0520248 B1 EP0520248 B1 EP 0520248B1
Authority
EP
European Patent Office
Prior art keywords
al2o3
coating
cef3
sio2
suspension
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.)
Expired - Lifetime
Application number
EP92109848A
Other languages
German (de)
French (fr)
Other versions
EP0520248A2 (en
EP0520248A3 (en
Inventor
Werner Dr. Weiss
Manfred Deisenhofer
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 EP0520248A2 publication Critical patent/EP0520248A2/en
Publication of EP0520248A3 publication Critical patent/EP0520248A3/en
Application granted granted Critical
Publication of EP0520248B1 publication Critical patent/EP0520248B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/38—Devices for influencing the colour or wavelength of the light
    • H01J61/40—Devices for influencing the colour or wavelength of the light by light filters; by coloured coatings in or on the envelope

Definitions

  • the invention relates to an electric lamp according to the preamble of patent claim 1.
  • High-pressure discharge lamps and also highly loaded halogen incandescent lamps generate a relatively high proportion of UV radiation during operation.
  • the lamp bulb of this lamp is made of quartz glass due to the high thermal stress, which has a high transparency for UV radiation in the range from approx. 400 nm to 200 nm.
  • the high-energy UV radiation is undesirable, even harmful.
  • it is harmful to health and leads to embrittlement of plastic parts.
  • the UV transparency of the lamp bulb must therefore be reduced.
  • UV-absorbing coating consists of a eutectic Al2O3.SiO2 mixture, which contains 0.05% to 10% UV-absorbing substances, e.g. TiO2 or CeO2 is doped.
  • the coating is produced by means of a suspension of Al2O3, SiO2 and the UV absorber in isopropyl alcohol with water, which is sprayed onto the lamp bulb, dried and baked.
  • the object of the invention is to reduce the UV transparency of the lamp bulb as much as possible in the case of electric lamps with quartz glass bulbs, without appreciably impairing its light transmission in the visible spectral range.
  • the transmittance of the lamp bulbs according to the invention for UV radiation is already greatly reduced even with small layer thicknesses of a few micrometers. It has been shown that coatings with CeF3 under otherwise identical conditions have a stronger UV-absorbing effect than coatings which have CeO2. Compared to the UV absorber TiO2 offers CeF3 the advantage that it also absorbs long-wave UV rays, while TiO2 essentially absorbs the short-wave UV component.
  • the CeF3 in the lamp bulb coatings according to the invention does not reduce the transparency of the lamp bulb for light from the visible spectral range if the layer thicknesses are not too great.
  • the manufacturing process requires significantly less time than that described in US-A-3,531,677 for the lamps disclosed therein.
  • Another advantage of the lamps according to the invention is that the tendency of quartz molecules to evaporate from the lamp bulb surface in a moist atmosphere and the associated surface roughening of the lamp bulb is reduced by the coating.
  • FIG. 1 A metal halide high-pressure discharge lamp for a motor vehicle headlight is shown in FIG.
  • This lamp has a discharge vessel 1 made of quartz glass, in which two electrodes 2 are arranged, each of which is electrically contacted via a molybdenum foil melt 3 and the current leads 4.
  • the discharge vessel 1 is held by one of the bulb shafts 5 in a plastic base (not shown) which, without the inventive measure, would become brittle due to the high-energy UV radiation generated in the discharge and transmitted by the discharge vessel 1, which would result in the premature failure of the discharge lamp.
  • the discharge vessel 1 is provided according to the invention with an approximately 5 - 10 »m thick coating 6 made of CeF3 with Al2O3.SiO2 in order to reduce the UV permeability of the discharge vessel 1.
  • the thickness of the coating 6 is optimized in such a way that the lamp bulb still appears clear despite the coating 6, so that its transparency to light from the visible spectral range is not impaired.
  • the coating 6 made of CeF3 with Al2O3.SiO2 also extends over the regions of the bulb shafts 5 immediately adjacent to the discharge vessel 1, which are also exposed to high thermal stress. As a result, the evaporation of quartz molecules from the surface of the discharge vessel 1, which is strongly heated during operation, and the bulb parts immediately adjacent to it are reduced.
  • the weight ratio of cerium fluoride CeF3 to Al2O3.SiO2 in the coating 6 is 2: 1, while the weight ratio of Al2O3 to SiO2 in the Al2O3.SiO2 mixture is approximately 1.7: 1.
  • the presence of Al2O3 in the coating 6 increases the solubility of the UV-absorbing CeF3 in the quartz melt to such an extent that sufficient UV absorption takes place in the coating 6.
  • FIG. 2 shows the transmittance of a quartz glass bulb for UV radiation and light the visible spectral range once without coating 6 and once with CeF3 + Al2O3.SiO2 coating 6, the thickness of which is approximately 5 - 10 »m. Transmittance 100% means that all the light generated in the lamp bulb (at the wavelength under consideration) transmits the lamp bulb.
  • a comparison of the two curves in the diagram in FIG. 2 shows that the lamp bulbs according to the invention with coating 6 have a significantly increased UV absorption, while light from the visible spectral range (400 nm to 600 nm) is not additionally weakened by coating 6.
  • the coating 6 is preferably carried out on the fully formed quartz glass bulb.
  • a suspension in alcohol is made from a mixture of cerium fluoride CeF3 and Al2O3.SiO2, the weight ratio of CeF3 to Al2O3. SiO2 is approximately 2: 1.
  • the weight ratio of Al2O3 to SiO2 in the mixture is approximately 1.7: 1.
  • the mixture is ground for at least 10 hours in a ball mill with the addition of spirit so that the grain size of the mixture is less than 300 mesh.
  • the suspension is then further diluted with alcohol, approximately in a ratio of 1: 5.
  • the finished suspension is dripped onto the lamp bulb while rotating the lamp bulb about its axial axis. But it can also be sprayed on or brushed on.
  • the coated part of the lamp bulb assumes a yellowish color. Then the coating in a H2 / O2 flame or burned in a town gas-air O2 flame while maintaining the axial rotation of the lamp bulb. The burn-in process takes about 2 seconds.
  • the coated part of the lamp bulb appears after the baking process, depending on the layer thickness, clear to slightly silky matt.
  • nitrocellulose can be added to the suspension as a binder instead of alcohol. To make the binder, five percent butyl acetate nitrocellulose is diluted with seven times the amount of alcohol. Four to six parts of this binder are then added to the suspension in the ball mill instead of pure alcohol in the manufacturing process described above. Instead of alcohol, acetone or butyl acetate are also suitable as diluents.
  • the coating according to the invention can be used for all types of lamps with a quartz glass bulb.
  • the coating according to the invention can be used particularly advantageously in the case of high-pressure discharge lamps without an outer envelope bulb and in the case of highly loaded halogen incandescent lamps for the photo / optics sector.

Description

Die Erfindung betrifft eine elektrische Lampe gemäß dem Oberbegriff des Patentanspruchs 1.The invention relates to an electric lamp according to the preamble of patent claim 1.

Hochdruckentladungslampen und auch hochbelastete Halogenglühlampen erzeugen beim Betrieb einen relativ hohen Anteil an UV-Strahlung. Der Lampenkolben dieser Lampe besteht wegen der starken thermischen Beanspruchung aus Quarzglas, das für UV-Strahlung im Bereich von ca. 400 nm bis 200 nm eine hohe Transparenz aufweist. Für viele Anwendungen ist die energiereiche UV-Strahlung unerwünscht, ja sogar schädlich. Sie ist beispielsweise gesundheitsschädlich und führt zur Versprödung von Kunststoffteilen. Bei Lampen, die nicht in einem UV-absorbierenden äußeren Hüllkolben angeordnet sind, und die nicht als UV-Strahler dienen, muß daher die UV-Transparenz des Lampenkolbens reduziert werden.High-pressure discharge lamps and also highly loaded halogen incandescent lamps generate a relatively high proportion of UV radiation during operation. The lamp bulb of this lamp is made of quartz glass due to the high thermal stress, which has a high transparency for UV radiation in the range from approx. 400 nm to 200 nm. For many applications, the high-energy UV radiation is undesirable, even harmful. For example, it is harmful to health and leads to embrittlement of plastic parts. In the case of lamps which are not arranged in a UV-absorbing outer envelope bulb and which do not serve as UV emitters, the UV transparency of the lamp bulb must therefore be reduced.

Aus der US-A-3 531 677 ist eine Hochdruckentladungslampe mit einem Entladungsgefäß aus Quarzglas bekannt, das eine UV-absorbierende Beschichtung aufweist. Die UV-absorbierende Beschichtung besteht aus einem eutektischen Al₂O₃.SiO₂-Gemisch, das mit 0,05 % bis 10 % UV-absorbierenden Substanzen, z.B. TiO₂ oder CeO₂, dotiert ist.From US-A-3 531 677 a high-pressure discharge lamp with a discharge vessel made of quartz glass is known, which has a UV-absorbing coating. The UV-absorbing coating consists of a eutectic Al₂O₃.SiO₂ mixture, which contains 0.05% to 10% UV-absorbing substances, e.g. TiO₂ or CeO₂ is doped.

Hergestellt wird die Beschichtung mittels einer Suspension von Al₂O₃, SiO₂ und dem UV-Absorber in Isopropylalkohol mit Wasser, die auf den Lampenkolben aufgesprüht, getrocknet und eingebrannt wird.The coating is produced by means of a suspension of Al₂O₃, SiO₂ and the UV absorber in isopropyl alcohol with water, which is sprayed onto the lamp bulb, dried and baked.

Untersuchungen haben gezeigt, daß die UV-Transparenz derartiger Lampen durch die UV-absorbierende Beschichtung nicht im gewünschten Maße reduziert wird. Außerdem ist der Herstellungsprozeß für diese beschichteten Lampenkolben, insbesondere der Trocknungsprozeß und das Einbrennen der Beschichtung relativ zeitaufwendig und für eine Massenproduktion zu kostspielig.Studies have shown that the UV transparency of such lamps is not reduced to the desired extent by the UV-absorbing coating. In addition, the manufacturing process for these coated lamp bulbs, in particular the drying process and the baking of the coating, is relatively time-consuming and too expensive for mass production.

Ferner ist es bekannt, das Quarzglas für den Lampenkolben mit UV-absorbierenden Ionen zu dotieren. Dieses Vorgehen führt allerdings zu einer Viskositätserniedrigung des Quarzglases, so daß die thermische Belastbarkeit und damit die Lichtausbeute der Lampe vermindert wird.It is also known to dope the quartz glass for the lamp bulb with UV-absorbing ions. However, this procedure leads to a lowering of the viscosity of the quartz glass, so that the thermal load capacity and thus the luminous efficiency of the lamp is reduced.

Der Erfindung liegt die Aufgabe zugrunde, bei elektrischen Lampen mit Quarzglaskolben die UV-Transparenz des Lampenkolbens möglichst stark zu reduzieren, ohne dabei seine Lichtdurchlässigkeit im sichtbaren Spektralbereich nennenswert zu beeinträchtigen.The object of the invention is to reduce the UV transparency of the lamp bulb as much as possible in the case of electric lamps with quartz glass bulbs, without appreciably impairing its light transmission in the visible spectral range.

Diese Aufgabe wird erfindungsgemäß durch die kennzeichnenden Merkmale des Patentanspruches 1 gelöst. Besonders vorteilhafte Ausführungen finden sich in den abhängigen Ansprüchen.This object is achieved by the characterizing features of claim 1. Particularly advantageous designs can be found in the dependent claims.

Der Transmissionsgrad der erfindungsgemäßen Lampenkolben für UV-Strahlung ist schon bei geringen Schichtdicken von wenigen Mikrometern bereits stark reduziert. Es hat sich gezeigt, daß Beschichtungen mit CeF₃ unter sonst gleichen Bedingungen eine stärkere UV-absorbierende Wirkung besitzen als Beschichtungen, die CeO₂ aufweisen. Gegenüber dem UV-Absorber TiO₂ bietet CeF₃ den Vorteil, daß es auch langwellige UV-Strahlen absorbiert, während TiO₂ im wesentlichen den kurzwelligen UV-Anteil absorbiert. Das CeF₃ in den erfindungsgemäßen Lampenkolbenbeschichtungen vermindert bei nicht zu großen Schichtdicken die Transparenz der Lampenkolben für Licht aus dem sichtbaren Spektralbereich nicht. Der Herstellungsprozeß erfordert erheblich weniger Zeitaufwand als der in der US-A-3 531 677 beschriebene für die dort offenbarten Lampen. Ein weiterer Vorteil der erfindungsgemäßen Lampen besteht darin, daß die Abdampfneigung von Quarzmolekülen aus der Lampenkolbenoberfläche in feuchter Atmosphäre und die damit verbundene Oberflächenaufrauhung des Lampenkolbens durch die Beschichtung vermindert wird.The transmittance of the lamp bulbs according to the invention for UV radiation is already greatly reduced even with small layer thicknesses of a few micrometers. It has been shown that coatings with CeF₃ under otherwise identical conditions have a stronger UV-absorbing effect than coatings which have CeO₂. Compared to the UV absorber TiO₂ offers CeF₃ the advantage that it also absorbs long-wave UV rays, while TiO₂ essentially absorbs the short-wave UV component. The CeF₃ in the lamp bulb coatings according to the invention does not reduce the transparency of the lamp bulb for light from the visible spectral range if the layer thicknesses are not too great. The manufacturing process requires significantly less time than that described in US-A-3,531,677 for the lamps disclosed therein. Another advantage of the lamps according to the invention is that the tendency of quartz molecules to evaporate from the lamp bulb surface in a moist atmosphere and the associated surface roughening of the lamp bulb is reduced by the coating.

Die Erfindung wird nachstehend anhand eines bevorzugten Ausführungsbeispiels näher erläutert. Es zeigen:

Figur 1
eine erfindungsgemäße Hochdruckentladungslampe
Figur 2
den Transmissionsgrad in Prozent aufgetragen (Y-Achse) in Abhängigkeit von der Wellenlänge der erzeugten Strahlung (X-Achse) für Quarzglaskolben mit (Kurve 2) und ohne (Kurve 1) die erfindungsgemäße Beschichtung.
The invention is explained below with reference to a preferred embodiment. Show it:
Figure 1
a high-pressure discharge lamp according to the invention
Figure 2
the transmittance is plotted in percent (Y axis) as a function of the wavelength of the radiation generated (X axis) for quartz glass bulbs with (curve 2) and without (curve 1) the coating according to the invention.

In Figur 1 ist eine Metallhalogenid-Hochdruckentladungslampe für einen Kfz-Scheinwerfer abgebildet. Diese Lampe besitzt ein Entladungsgefäß 1 aus Quarzglas, in dem zwei Elektroden 2 angeordnet sind, die jeweils über eine Molybdänfolieneinschmelzung 3 und die Stromzuführungen 4 elektrisch kontaktiert werden.A metal halide high-pressure discharge lamp for a motor vehicle headlight is shown in FIG. This lamp has a discharge vessel 1 made of quartz glass, in which two electrodes 2 are arranged, each of which is electrically contacted via a molybdenum foil melt 3 and the current leads 4.

Das Entladungsgefäß 1 wird von einem der Kolbenschäfte 5 in einem Kunststoffsockel (nicht abgebildet) gehaltert, der ohne erfindungsgemäße Maßnahme durch die in der Entladung erzeugte und vom Entladungsgefäß 1 transmittierte energiereiche UV-Strahlung verspröden würde, was den vorzeitigen Ausfall der Entladungslampe zur Folge hätte. Das Entladungsgefäß 1 ist erfindungsgemäß außen mit einer ca. 5 - 10 »m dicken Beschichtung 6 aus CeF₃ mit Al₂O₃.SiO₂ versehen, um die UV-Durchlässigkeit des Entladungsgefäßes 1 zu vermindern. Die Dicke der Beschichtung 6 ist dahingehend optimiert, daß der Lampenkolben trotz der Beschichtung 6 noch klar erscheint, so daß seine Transparenz für Licht aus dem sichtbaren Spektralbereich nicht beeinträchtigt wird. Die Beschichtung 6 aus CeF₃ mit Al₂O₃.SiO₂ erstreckt sich auch über die an das Entladungsgefäß 1 unmittelbar angrenzenden Bereiche der Kolbenschäfte 5, die ebenfalls einer hohen thermischen Belastung ausgesetzt sind. Dadurch wird das Abdampfen von Quarzmolekülen aus der im Betrieb stark erhitzten Oberfläche des Entladungsgefäßes 1 und der unmittelbar daran angrenzenden Kolbenteile reduziert. Das Gewichtsverhältnis von Cerfluorid CeF₃ zu Al₂O₃.SiO₂ in der Beschichtung 6 beträgt 2:1, während das Gewichtsverhältnis von Al₂O₃ zu SiO₂ im Al₂O₃.SiO₂-Gemisch ungefähr 1,7:1 beträgt. Durch die Anwesenheit von Al₂O₃ in der Beschichtung 6 wird die Lösbarkeit des UV-absorbierenden CeF₃ in der Quarzschmelze soweit erhöht, daß eine ausreichende UV-Absorption in der Beschichtung 6 stattfindet.The discharge vessel 1 is held by one of the bulb shafts 5 in a plastic base (not shown) which, without the inventive measure, would become brittle due to the high-energy UV radiation generated in the discharge and transmitted by the discharge vessel 1, which would result in the premature failure of the discharge lamp. The discharge vessel 1 is provided according to the invention with an approximately 5 - 10 »m thick coating 6 made of CeF₃ with Al₂O₃.SiO₂ in order to reduce the UV permeability of the discharge vessel 1. The thickness of the coating 6 is optimized in such a way that the lamp bulb still appears clear despite the coating 6, so that its transparency to light from the visible spectral range is not impaired. The coating 6 made of CeF₃ with Al₂O₃.SiO₂ also extends over the regions of the bulb shafts 5 immediately adjacent to the discharge vessel 1, which are also exposed to high thermal stress. As a result, the evaporation of quartz molecules from the surface of the discharge vessel 1, which is strongly heated during operation, and the bulb parts immediately adjacent to it are reduced. The weight ratio of cerium fluoride CeF₃ to Al₂O₃.SiO₂ in the coating 6 is 2: 1, while the weight ratio of Al₂O₃ to SiO₂ in the Al₂O₃.SiO₂ mixture is approximately 1.7: 1. The presence of Al₂O₃ in the coating 6 increases the solubility of the UV-absorbing CeF₃ in the quartz melt to such an extent that sufficient UV absorption takes place in the coating 6.

Figur 2 zeigt zum Vergleich den Transmissionsgrad eines Quarzglaskolbens für UV-Strahlung und Licht aus dem sichtbaren Spektralbereich einmal ohne Beschichtung 6 und einmal mit CeF₃ + Al₂O₃.SiO₂-Beschichtung 6, deren Dicke ungefähr 5 - 10 »m beträgt. Transmissionsgrad 100 % bedeutet, daß sämtliches, im Lampenkolben erzeugtes Licht (bei der betrachteten Wellenlänge) den Lampenkolben transmittiert.For comparison, FIG. 2 shows the transmittance of a quartz glass bulb for UV radiation and light the visible spectral range once without coating 6 and once with CeF₃ + Al₂O₃.SiO₂ coating 6, the thickness of which is approximately 5 - 10 »m. Transmittance 100% means that all the light generated in the lamp bulb (at the wavelength under consideration) transmits the lamp bulb.

Der Vergleich beider Kurven im Diagramm der Figur 2 zeigt, daß die erfindungsgemäßen Lampenkolben mit Beschichtung 6 eine deutlich erhöhte UV-Absorption aufweisen, während Licht aus dem sichtbaren Spektralbereich (400 nm bis 600 nm) durch die Beschichtung 6 keine zusätzliche Schwächung erfährt.A comparison of the two curves in the diagram in FIG. 2 shows that the lamp bulbs according to the invention with coating 6 have a significantly increased UV absorption, while light from the visible spectral range (400 nm to 600 nm) is not additionally weakened by coating 6.

Die Beschichtung 6 wird vorzugsweise am fertig geformten Quarzglaskolben vorgenommen. Dazu wird eine Suspension in Spiritus aus einer Mischung von Cerfluorid CeF₃ und Al₂O₃.SiO₂ hergestellt, wobei das Gewichtsverhältnis von CeF₃ zu Al₂O₃. SiO₂ ca. 2:1 beträgt. Das Gewichtsverhältnis von Al₂O₃ zu SiO₂ in der Mischung beträgt ungefähr 1,7:1. Das Gemisch wird mindestens 10 Stunden in einer Kugelmühle unter Zusatz von Spiritus gemahlen, so daß die Korngröße der Mischung kleiner als 300 mesh ist. Anschließend wird die Suspension weiter mit Spiritus, etwa im Verhältnis 1:5, verdünnt. Die fertige Suspension wird unter Drehung des Lampenkolbens um seine axiale Achse auf den Lampenkolben aufgetropft. Sie kann aber auch aufgesprüht oder aufgepinselt werden. Beim anschließenden Trocknungsprozeß, der bei einer Temperatur von ca. 400°C erfolgt und etwa 10 Sekunden dauert, nimmt der beschichtete Teil des Lampenkolbens eine gelbliche Färbung an. Danach wird die Beschichtung in einer H₂/O₂-Flamme oder in einer Stadtgas-Luft-O₂-Flamme unter Beibehaltung der axialen Drehung des Lampenkolbens eingebrannt. Der Einbrennvorgang benötigt etwa 2 Sekunden. Der beschichtete Teil des Lampenkolbens erscheint nach dem Einbrennvorgang, je nach Schichtdicke, klar bis leicht seidenmatt. Nach dem Mahlvorgang in der Kugelmühle kann der Suspension anstelle von Spiritus auch Nitrocellulose als Binder zugesetzt werden. Zur Herstellung des Binders wird fünfprozentige Butylacetat-Nitrocellulose mit der siebenfachen Menge Spiritus verdünnt. Der Suspension in der Kugelmühle werden sodann vier bis sechs Teile dieses Binders anstelle des reinen Spiritus im oben beschriebenen Herstellungsverfahren zugegeben. Statt Spiritus eignen sich als Verdünnungsmittel auch Aceton oder Butylacetat.The coating 6 is preferably carried out on the fully formed quartz glass bulb. For this purpose, a suspension in alcohol is made from a mixture of cerium fluoride CeF₃ and Al₂O₃.SiO₂, the weight ratio of CeF₃ to Al₂O₃. SiO₂ is approximately 2: 1. The weight ratio of Al₂O₃ to SiO₂ in the mixture is approximately 1.7: 1. The mixture is ground for at least 10 hours in a ball mill with the addition of spirit so that the grain size of the mixture is less than 300 mesh. The suspension is then further diluted with alcohol, approximately in a ratio of 1: 5. The finished suspension is dripped onto the lamp bulb while rotating the lamp bulb about its axial axis. But it can also be sprayed on or brushed on. During the subsequent drying process, which takes place at a temperature of approx. 400 ° C and lasts about 10 seconds, the coated part of the lamp bulb assumes a yellowish color. Then the coating in a H₂ / O₂ flame or burned in a town gas-air O₂ flame while maintaining the axial rotation of the lamp bulb. The burn-in process takes about 2 seconds. The coated part of the lamp bulb appears after the baking process, depending on the layer thickness, clear to slightly silky matt. After grinding in a ball mill, nitrocellulose can be added to the suspension as a binder instead of alcohol. To make the binder, five percent butyl acetate nitrocellulose is diluted with seven times the amount of alcohol. Four to six parts of this binder are then added to the suspension in the ball mill instead of pure alcohol in the manufacturing process described above. Instead of alcohol, acetone or butyl acetate are also suitable as diluents.

Die erfindungsgemäße Beschichtung ist für alle Lampentypen mit einem Quarzglaskolben anwendbar. Besonders vorteilhaft ist die erfindungsgemäße Beschichtung bei Hochdruckentladungslampen ohne äußeren Hüllkolben und bei hochbelasteten Halogenglühlampen für den Foto/Optik-Bereich anwendbar.The coating according to the invention can be used for all types of lamps with a quartz glass bulb. The coating according to the invention can be used particularly advantageously in the case of high-pressure discharge lamps without an outer envelope bulb and in the case of highly loaded halogen incandescent lamps for the photo / optics sector.

Claims (10)

  1. Electric lamp with a quartz glass bulb (1) having a UV-absorbing coating (6), characterized in that the UV-absorbing coating (6) consists of a glazing which contains cerium fluoride (CeF₃) and a mixture of Al₂O₃ and SiO₂ (Al₂O₃·SiO₂).
  2. Electric lamp according to Claim 1, characterized in that the CeF₃/Al₂O₃·SiO₂ weight ratio in the coating (6) is between 1:1 and 3:1.
  3. Electric lamp according to Claim 2, characterized in that the CeF₃/Al₂O₃·SiO₂ weight ratio in the coating (6) is 2:1.
  4. Electric lamp according to Claim 1, characterized in that the lamp is a high-pressure discharge lamp whose discharge vessel (1) consists of quartz glass which is provided on its outer surface with a UV-absorbing coating (6).
  5. Electric lamp according to Claim 1, characterized in that the lamp is an incandescent halogen lamp whose bulb consists of quartz glass which has a UV-absorbing coating on its outer surface.
  6. Production process for an electric lamp according to Claim 1, characterized in that the process comprises the following fabrication steps:
    - preparation of a suspension of CeF₃ and Al₂O₃·SiO₂ in a diluent, the CeF₃/Al₂O₃·SiO₂ weight ratio being between 1:1 and 3:1,
    - grinding of the suspension, so that the grain size of the solid substances in the suspension is smaller than 300 mesh,
    - dilution of the suspension with the diluent,
    - application of the suspension to a surface of the quartz glass bulb and subsequent drying of the coating,
    - heating of the coated quartz glass bulb at about 400°C,
    - baking of the coating
  7. Manufacturing process according to Claim 6, characterized in that the CeF₃/Al₂O₃·SiO₂ weight ratio is 2:1.
  8. Manufacturing process according to Claim 6, characterized in that a binder is added after the step of grinding the suspension.
  9. Manufacturing process according to Claim 8, characterized in that the binder used is five percent of nitrocellulose in butyl acetate, diluted with alcohol.
  10. Manufacturing process according to Claim 6, characterized in that the diluent used is alcohol.
EP92109848A 1991-06-24 1992-06-11 Electric lamp Expired - Lifetime EP0520248B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4120797 1991-06-24
DE4120797A DE4120797A1 (en) 1991-06-24 1991-06-24 ELECTRIC LAMP

Publications (3)

Publication Number Publication Date
EP0520248A2 EP0520248A2 (en) 1992-12-30
EP0520248A3 EP0520248A3 (en) 1993-02-10
EP0520248B1 true EP0520248B1 (en) 1995-03-22

Family

ID=6434613

Family Applications (1)

Application Number Title Priority Date Filing Date
EP92109848A Expired - Lifetime EP0520248B1 (en) 1991-06-24 1992-06-11 Electric lamp

Country Status (5)

Country Link
US (1) US5336969A (en)
EP (1) EP0520248B1 (en)
JP (1) JPH05190142A (en)
CA (1) CA2064330A1 (en)
DE (2) DE4120797A1 (en)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5552671A (en) * 1995-02-14 1996-09-03 General Electric Company UV Radiation-absorbing coatings and their use in lamps
US5614151A (en) * 1995-06-07 1997-03-25 R Squared Holding, Inc. Electrodeless sterilizer using ultraviolet and/or ozone
JP3415533B2 (en) * 2000-01-12 2003-06-09 エヌイーシーマイクロ波管株式会社 High pressure discharge lamp
JP3437149B2 (en) * 2000-06-30 2003-08-18 松下電器産業株式会社 Fluorescent lamp and fluorescent lamp device
DE10358676A1 (en) * 2003-12-12 2005-07-07 Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH Light bulb with activating effect
CN101421820A (en) * 2004-03-02 2009-04-29 皇家飞利浦电子股份有限公司 Be used to make the method for high-intensity discharge lamp
JP4897618B2 (en) * 2007-08-28 2012-03-14 ハリソン東芝ライティング株式会社 UV light source
DE102010042557A1 (en) * 2009-10-21 2011-04-28 Osram Gesellschaft mit beschränkter Haftung halogen bulb

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2974052A (en) * 1960-07-11 1961-03-07 Owens Illinois Glass Co Ultraviolet light absorbing glass
US3148300A (en) * 1961-08-04 1964-09-08 Gen Electric Lamp having envelope of glass opaque to ultraviolet radiation
US3531677A (en) * 1966-12-14 1970-09-29 Sylvania Electric Prod Quartz glass envelope with radiation-absorbing glaze
JPH0719567B2 (en) * 1987-02-27 1995-03-06 ウシオ電機株式会社 Quartz for arc tubes
US5214345A (en) * 1989-03-28 1993-05-25 Sumitomo Cement Company, Ltd. Ultraviolet ray-shielding agent and tube

Also Published As

Publication number Publication date
DE59201710D1 (en) 1995-04-27
EP0520248A2 (en) 1992-12-30
CA2064330A1 (en) 1992-12-25
US5336969A (en) 1994-08-09
DE4120797A1 (en) 1993-01-07
JPH05190142A (en) 1993-07-30
EP0520248A3 (en) 1993-02-10

Similar Documents

Publication Publication Date Title
EP0706201B1 (en) Mercury vapour lamp with short arc
DE69735822T2 (en) OPTICAL INTERFERENCE CONTROL FOR EXTREME TEMPERATURE RATIOS
DE69909575T2 (en) Ultraviolet absorbing and yellow light filtering glasses for lamp bulbs
DE2624897A1 (en) ALUMINUM OXYDE COVERS FOR MERCURY VAPOR LAMPS
EP0520248B1 (en) Electric lamp
EP3150562B1 (en) Use of optical filter material made of doped quartz glass and uv lamp containing the optical filter material
DE2530195A1 (en) HIGH POWER ARC DISCHARGE LAMP
EP1447615B1 (en) Pulsed sun simulator with improved homogeneity
DE3227096A1 (en) OPTICAL COATINGS SUITABLE FOR HIGH TEMPERATURES
DE2611894A1 (en) UV LUMINOUS DISCHARGE LAMP WITH REFLECTOR FILM INSIDE
EP0663684A2 (en) Reflector lamp
EP0339130A2 (en) Lighting fixture with halogen lamp
EP0407548B1 (en) Deuterium lamp for spectral analysis devices
EP0986093B1 (en) Incandescent lamp
EP0695723B1 (en) Quartz glass and electric lamp with quartz glass elements
DE2852048C3 (en) Process for producing a casing from polycrystalline, transparent aluminum oxide for high-pressure vapor discharge lamps
DD289850A5 (en) GEFAERTE ELECTRIC LAMP
DE2418131C3 (en) Fluorescent lamp with window
DE1539560B2 (en) Reflector fluorescent lamp
DE2355268C2 (en) Low-pressure mercury vapor discharge lamp and process for their manufacture
DE69829631T2 (en) Sealing arrangement of a tube lamp
DE2711733A1 (en) SODIUM VAPOR HIGH PRESSURE DISCHARGE LAMP
DE2644821A1 (en) FLUORESCENT LAMP WITH REFLECTIVE LAYER
EP0290669B1 (en) Hydrogen lamp and method for production thereof
EP0287706A2 (en) Hydrogen discharge lamp and method of manufacturing it

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

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE FR GB IT

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE FR GB IT

17P Request for examination filed

Effective date: 19930308

17Q First examination report despatched

Effective date: 19940628

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: 59201710

Country of ref document: DE

Date of ref document: 19950427

ITF It: translation for a ep patent filed

Owner name: STUDIO JAUMANN

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

Effective date: 19950605

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

Ref country code: GB

Payment date: 19980511

Year of fee payment: 7

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

Ref country code: FR

Payment date: 19980624

Year of fee payment: 7

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

Ref country code: DE

Payment date: 19980819

Year of fee payment: 7

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: 19990611

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: 19990630

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

Effective date: 19990611

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 NON-PAYMENT OF DUE FEES

Effective date: 20000503

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

Effective date: 20050611