EP0274611B1 - Illuminating arrangement for microwave ovens, in particular for domestic ovens - Google Patents

Illuminating arrangement for microwave ovens, in particular for domestic ovens Download PDF

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Publication number
EP0274611B1
EP0274611B1 EP87116931A EP87116931A EP0274611B1 EP 0274611 B1 EP0274611 B1 EP 0274611B1 EP 87116931 A EP87116931 A EP 87116931A EP 87116931 A EP87116931 A EP 87116931A EP 0274611 B1 EP0274611 B1 EP 0274611B1
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EP
European Patent Office
Prior art keywords
bulb
cooking space
filament
oven according
lamp
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
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EP87116931A
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German (de)
French (fr)
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EP0274611A1 (en
Inventor
Günter Dipl.-Ing. Hammerl
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BOSCH-SIEMENS HAUSGERAETE GMBH
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Individual
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Priority to AT87116931T priority Critical patent/ATE75021T1/en
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/80—Apparatus for specific applications
    • H05B6/806—Apparatus for specific applications for laboratory use
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
    • F24C15/00—Details
    • F24C15/008—Illumination for oven cavities
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/6444—Aspects relating to lighting devices in the microwave cavity
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/76—Prevention of microwave leakage, e.g. door sealings

Definitions

  • the present invention relates to an oven, in particular a domestic oven, with a closed cooking space, a microwave generator for applying microwaves of a certain basic frequency to the cooking space, and with a lighting device using an incandescent lamp which is placed on a lamp holder from outside the cooking space via electrical connecting lines is powered.
  • the incandescent filament of known lamp arrangements can and is made to glow solely by the action of these currents. If these currents are superimposed on the currents supplied for continuous lighting, the light bulbs normally used would be destroyed quickly because of overload. Because the electromagnetic magnetic field inside of the cooking space, not least because of this, in order to achieve a largely uniform exposure to the cooking space, when it moves, at least the lighting devices exposed to the microwave energy of the lighting devices known to be used intermittently shine intermittently. For these reasons, it is common practice to provide measures to prevent or at least reduce the radiation of the microwave energy onto the incandescent lamp of the lighting device. The most common protective measure is to shield the lighting device from the space to which microwave energy can be applied by means of a so-called pinhole made of metallic material.
  • the perforated panel Since the incandescent lamps should be accessible and replaceable from the cooking space, particularly in built-in appliances, the perforated panel must be releasably attached to the cooking space wall, which in turn causes problems for the microwave shielding.
  • the luminous efficiency which is greatly reduced when passing through the pinhole, is particularly disadvantageous. In order to achieve sufficient lighting in the cooking space, correspondingly powerful lamps must be used, which in turn create additional problems due to their strong heat development.
  • a lighting device for microwave ovens has become known (EP-A-0120 536), in which a relatively slim lamp is arranged behind the wall plane in a shaft with a defined distance of the filament from the wall with respect to the microwave chamber, in order to influence the microwave of the lamp and to face outside.
  • a lamp for illuminating the furnace space substantially reduces the use of the lamp's inherent luminosity.
  • it is necessary, or at least to strive, that the luminosity radiated forward from the shaft is distributed in the oven space by a suitably designed and effective cover.
  • the object of the invention is to provide a lighting device which, without the unfavorable side effects described, caused by the effects of the microwave properties, ensures good lighting of a cooking space which can be subjected to microwave energy.
  • an incandescent lamp with substantially parallel and equally long filament carriers and with a filament arranged in the glass bulb between the ends of the filament carriers with a length extension within which all distances between any points of the Filament correspond to a maximum of 10% of the wavelength of the basic microwave frequency that can be radiated into the cooking space, arranged freely protruding from the cooking space wall into the cooking space.
  • an incandescent lamp for low voltages of at most 30 volts e.g. to use an incandescent lamp for a connection voltage of 12 volts.
  • the use of halogen lamps is preferred.
  • Incandescent lamps of this type usually also meet the invention, which further improves refinement design criteria, according to which the filament carrier of the lamp and any points on the filament of the incandescent lamp have a maximum distance of 1/16 of the basic microwave frequency radiated into the cooking space. It is also advantageous in a further development of the invention to use an incandescent lamp whose incandescent filament carriers which are guided through the cooking base of the incandescent lamp are designed as terminating plug pins.
  • the lamp holder is arranged on the cooking chamber wall pointing into the cooking chamber and its connecting wires, which are led through holes in the cooking chamber wall, have a metallic shielding jacket grounded with the metallic cooking chamber wall.
  • the light bulbs are supplied with power from the public supply network with the corresponding voltages, for example 220 V. These have to be converted for the lamps with low voltage connection values used according to the invention.
  • conventional transformers are preferably used, whose inductance of their own opposes the remaining low energy absorbed by the incandescent lamp with a practically infinitely high resistance. This prevents a more extensive flow of current, which could be attributed to the incandescent lamp located in the cooking space due to the microwave radiation, through the connecting lines for the incandescent lamp.
  • the incandescent lamp protruding into the cooking space is covered by a glass hood opposite the cooking space.
  • an illumination device is created which no longer poses any significant problems with regard to the microwave tightness of the cooking chamber with respect to the surroundings.
  • the design and dimensioning, in particular of the filament carrier and of the filament ensures that the antenna effect of the incandescent lamp for receiving the microwave energy radiated into the microwave space is insignificantly low. Since the resistance values of the filaments in lamps with low voltage connection values are also low, currents which may be induced in the lamp construction can also be balanced out without problems, without the filament being adversely affected.
  • the feedthroughs through the cooking chamber wall now only require the diameter of the shielded power supply connections, so that there are no difficulties in producing and ensuring the microwave tightness.
  • the arrangement of the incandescent lamp within the cooking space without a metallic screen grille surrounding it also has the advantage that the entire luminosity of the incandescent lamp is available within the cooking space.
  • the connected load value for the incandescent lamps can thus be dimensioned smaller and the power losses, which have an effect as radiated heat, are significantly reduced compared to shielded lamps. When using halogen lamps, a bright white light is provided.
  • FIGS. 1 to 3 show, in schematic views, lighting devices arranged in three different variants on the wall of the cooking space and projecting into the cooking space for a domestic oven to which microwave energy can be applied.
  • connector pins 10 of a halogen lamp 11 are inserted. These pins 10 are continued through the glass base 12 of the halogen lamp 11 as an essentially parallel filament carrier 13. A coiled filament 14 is stretched between the free ends of the filament carrier 13 within the glass bulb of the halogen lamp 11.
  • the distance between the connector pins and the continued filament holder is approx. 4 mm, while the length of the filament is approx. 6 mm.
  • the connection voltage for the halogen lamp is 12 volts. Since the halogen lamp 11 projects freely into the cooking space, a connected load of 5 watts may be sufficient.
  • the halogen lamp 11 is covered by a glass hood 15 opposite the cooking chamber 1, so that protection against unintentional contact and against damage to the halogen lamp 11 is provided.
  • FIGS. 2 and 3 show variants with regard to the arrangement of the lamp holder 3 ⁇ and the incandescent lamp 11 for the cooking chamber wall 2 ⁇ or 2 ⁇ , which in this area has an expression 16 ⁇ or 16 ⁇ , which may be present anyway, from the cooking chamber 1.
  • the glass hood 15 ⁇ or 15 ⁇ is detachably fastened in this recess of the cooking space wall 2 ⁇ or 2 ⁇ using conventional measures.
  • 2 is arranged on the side of the cooking space wall 2 ⁇ facing the cooking space 1, according to FIG. 3 on the side of the cooking space wall 2 ⁇ facing away from the cooking space 1.
  • the connecting pins 10 of the light bulb 11 protrude through two holes 6 appris of the cooking space wall 2 ⁇ into the lamp holder 3 ⁇ .
  • the shield 7 ⁇ is pulled around this lamp holder up to the cooking chamber wall 2 ⁇ .

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • General Health & Medical Sciences (AREA)
  • Clinical Laboratory Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Electric Ovens (AREA)
  • Constitution Of High-Frequency Heating (AREA)
  • Electric Stoves And Ranges (AREA)

Abstract

An oven has a baking space wall at least partly defining a closed baking chamber to be acted upon by microwave energy with a given basic microwave frequency capable of being radiated into the baking space with a given wavelength. A lighting device for the oven includes a bulb holder, an incandescent bulb mounted on the bulb holder and protruding freely into the baking space from the baking space wall without electromagnetic shielding, and electrical connection lines supplying the incandescent bulb with current from outside the baking chamber. The incandescent bulb has a glass bulb, incandescent filament holders of equal length extending substantially, parallel and alongside one another, and an incandescent filament disposed between ends of the incandescent filament holders in the glass bulb. The filament has a longitudinal extension within which all spacings between given points along the incandescent filament are equivalent to a maximum of 10% of the given wavelength.

Description

Die vorliegende Erfindung bezieht sich auf einen Ofen, insbesondere Haushaltsbackofen, mit einem geschlossenen Garraum, einem Mikrowellengenerator zum Beaufschlagen des Garraums mit Mikrowellen einer bestimmten Grundfrequenz, sowie mit einer Beleuchtungseinrichtung unter Verwendung einer Glühlampe, die aufgesetzt auf einen Lampenträger von außerhalb des Garraums über elektrische Anschlußleitungen mit Strom versorgt wird.The present invention relates to an oven, in particular a domestic oven, with a closed cooking space, a microwave generator for applying microwaves of a certain basic frequency to the cooking space, and with a lighting device using an incandescent lamp which is placed on a lamp holder from outside the cooking space via electrical connecting lines is powered.

Bei Mikrowellenöfen oder Mikrowellenherden mit oder ohne zusätzlichen thermischen Heizquellen dienen zur Ausleuchtung des Garraums Beleuchtungseinrichtungen mit Glühfadenlampen, die üblicherweise im Bereich einer der Seitenwandungen oder der oberen Wandung des Garraums an der Garraumwand angeordnet sind. In diesem Zusammenhang ist es bekanntermaßen erforderlich, in der Garraumwandung eine relativ große Öffnung vorzusehen, hinter welcher der Lampensockel der Beleuchtungseinrichtung außerhalb des Ofenraums befestigt ist. Es sind nunmehr in diesem Bereich besondere Maßnahmen zu treffen, um ein Austreten von Mikrowellen durch diese Öffnungen zu verhindern. Darüberhinaus ist auch der Tatsache Rechnung zu tragen, daß die Glühlampen mit ihren Glühfaden und Glühfadenträgern als Empfangsantenne für die in den Garraum eingestrahlte Mikrowellenenergie wirken. Die in diese Lampensysteme induzierte Spannungen erzeugen Ströme, welche unter anderem Stromflüsse über die Glühfäden verursachen. Allein durch die Beaufschlagung durch diese Ströme können und werden die Glühwendel bekannter Lampenanordnungen zum Glühen gebracht. Überlagern diese Ströme die für eine stetige Beleuchtung zugeführten Ströme, so würden üblicherweise benutzte Glühlampen wegen Überlastung schnell zerstört werden. Da das elektromangnetische Mikrowellenfeld innerhalb des Garraums nicht zuletzt deswegen, um eine weitgehende gleichmäßige Beaufschlagung des Garraums zu erzielen, in diesem wandert, leuchten zumindest die der Mikrowellenenergie ausgesetzten Beleuchtungseinrichtungen der bekannterweise eingesetzten Beleuchtungseinrichtungen störenderweise intermittierend. Aus diesen Gründen ist es allgemein geübte Praxis, Maßnahmen vorzusehen, um eine Einstrahlung der Mikrowellenenergie auf die Glühlampe der Beleuchtungseinrichtung zu verhindern, zumindest aber herabzusetzen. Die gebräuchlichste Schutzmaßnahme besteht darin, die Beleuchtungseinrichtung gegenüber dem mit Mikrowellenenergie beaufschlagbaren Raum durch eine sogenannte Lochblende aus metallischem Material abzuschirmen. Da die Glühlampen insbesondere bei Einbaugeräten vom Garraum aus zugänglich und auswechselbar sein sollten, muß die Lochblende lösbar an der Garraumwandung befestigt werden, was wiederum Probleme für die Mikrowellenabschirmung verursacht. Besonders nachteilig wirkt sich aber die stark beim Durchgang durch die Lochblende reduzierte Lichtausbeute aus. Um eine genügende Beleuchtung des Garraums zu erreichen, müssen entsprechend leistungsstarke Lampen zum Einsatz gebracht werden, die wiederum ob ihrer starken Wärmeentwicklung zusätzliche Probleme schaffen.In the case of microwave ovens or microwave ovens with or without additional thermal heating sources, lighting devices with filament lamps are used to illuminate the cooking space, which are usually arranged in the region of one of the side walls or the top wall of the cooking space on the cooking space wall. In this connection, it is known that it is necessary to provide a relatively large opening in the cooking space wall, behind which the lamp base of the lighting device is fastened outside the oven space. Special measures must now be taken in this area to prevent microwaves from escaping through these openings. In addition, the fact that the incandescent lamps with their filament and filament carriers act as a receiving antenna for the microwave energy radiated into the cooking chamber must also be taken into account. The voltages induced in these lamp systems generate currents which, among other things, cause current to flow through the filaments. The incandescent filament of known lamp arrangements can and is made to glow solely by the action of these currents. If these currents are superimposed on the currents supplied for continuous lighting, the light bulbs normally used would be destroyed quickly because of overload. Because the electromagnetic magnetic field inside of the cooking space, not least because of this, in order to achieve a largely uniform exposure to the cooking space, when it moves, at least the lighting devices exposed to the microwave energy of the lighting devices known to be used intermittently shine intermittently. For these reasons, it is common practice to provide measures to prevent or at least reduce the radiation of the microwave energy onto the incandescent lamp of the lighting device. The most common protective measure is to shield the lighting device from the space to which microwave energy can be applied by means of a so-called pinhole made of metallic material. Since the incandescent lamps should be accessible and replaceable from the cooking space, particularly in built-in appliances, the perforated panel must be releasably attached to the cooking space wall, which in turn causes problems for the microwave shielding. However, the luminous efficiency, which is greatly reduced when passing through the pinhole, is particularly disadvantageous. In order to achieve sufficient lighting in the cooking space, correspondingly powerful lamps must be used, which in turn create additional problems due to their strong heat development.

Es ist auch schon vorgeschlagen worden, die Glühlampen hinter die Garraumwandung zurückzusetzen und den Aufnahmeschacht für die Glühlampe in Form von sogenannten Mikrowellenfallen auszugestalten. Auch diese Maßnahme stößt bei der praktischen Realisierung auf erhebliche Schwierigkeiten und die aus dem Garraum zurückgesetzte Glühwendel führt ebenfalls zu einer verminderten Lichtausbeute.It has also been proposed to put the light bulbs back behind the cooking space wall and to design the receiving shaft for the light bulb in the form of so-called microwave traps. This measure also encounters considerable difficulties in practical implementation and the incandescent filament set back from the cooking space also leads to a reduced light yield.

So ist eine Beleuchtungseinrichtung für Mikrowellenöfen bekannt geworden (EP-A-0120 536), bei der eine relativ schlanke Lampe bezüglich des mit Mikrowelle beaufschlagten Ofenraumes hinter der Wandungsebene in einem Schacht mit definiertem Abstand der Leuchtwendel von der Wandung angeordnet ist, um Mikrowellenbeeinflussung der Lampe und nach außen zu begegnen. Eine derartige Anordnung einer Lampe zur Beleuchtung des Ofenraumes reduziert im wesentlichen Maße die Nutzung der an sich vorhandenen Leuchtkraft der Lampe. Darüber hinaus ist es erforderlich, oder zumindest anzustreben, daß die aus dem Schacht nach vorne abgestrahlte Leuchtkraft durch eine entsprechend gestaltete und wirkende Abdeckung in dem Backofenraum verteilt wird.Thus, a lighting device for microwave ovens has become known (EP-A-0120 536), in which a relatively slim lamp is arranged behind the wall plane in a shaft with a defined distance of the filament from the wall with respect to the microwave chamber, in order to influence the microwave of the lamp and to face outside. Such an arrangement of a lamp for illuminating the furnace space substantially reduces the use of the lamp's inherent luminosity. In addition, it is necessary, or at least to strive, that the luminosity radiated forward from the shaft is distributed in the oven space by a suitably designed and effective cover.

Der Erfindung liegt die Aufgabe zugrunde, eine Beleuchtungseinrichtung bereitzustellen, die ohne die geschilderten ungünstigen, durch die Auswirkungen der Mikrowelleneigenschaften hervorgerufenen Nebenerscheinungen eine gute Beleuchtung eines mit Mikrowellenenergie beaufschlagbaren Garraums gewährleistet.The object of the invention is to provide a lighting device which, without the unfavorable side effects described, caused by the effects of the microwave properties, ensures good lighting of a cooking space which can be subjected to microwave energy.

Bei einer dieser Aufgabenstellung gerecht werdenden Beleuchtungseinrichtung ist erfindungsgemäß eine Glühlampe mit im wesentlichen nebeneinander parallel verlaufenden und gleich langen Glühfadenträgern und mit einem im Glaskolben zwischen den Enden der Glühfadenträger angeordneten Glühfaden mit einer Längenausdehnung, innerhalb der alle Abstände zwischen beliebigen Punkten des Glühfadens maximal 10 % der Wellenlänge der in den Garraum einstrahlbaren Mikrowellen-Grundfrequenz entsprechen, von der Garraumwandung in den Garraum frei hineinragend angeordnet.In a lighting device that meets this task, according to the invention, an incandescent lamp with substantially parallel and equally long filament carriers and with a filament arranged in the glass bulb between the ends of the filament carriers with a length extension within which all distances between any points of the Filament correspond to a maximum of 10% of the wavelength of the basic microwave frequency that can be radiated into the cooking space, arranged freely protruding from the cooking space wall into the cooking space.

Bevorzugterweise ist im Rahmen der Erfindung eine Glühlampe für niedere Spannungen von maximal 30 Volt, z.B. eine Glühlampe für eine Anschlußspannung von 12 Volt zu verwenden. Zur Erzielung hoher Lichtausbeute bei kleinen Abmessungen bietet sich die Verwendung von Halogenlampen bevorzugterweise an. Derartige Glühlampen erfüllen üblicherweise auch die Erfindung verbessert weiterbildende Ausgestaltungskriterien, wonach der Glühfadenträger der Lampe und beliebige Punkte des Glühfadens der Glühlampe maximal einen Abstand von 1/16 der in den Garraum eingestrahlten Mikrowellen-Grundfrequenz aufweisen. Ebenso ist es die Erfindung weiterbildend vorteilhaft, eine Glühlampe zu verwenden, deren durch den Garsockel der Glühlampe hindurchgeführte Glühfadenträger zu Abschluß-Steckstiften ausgebildet sind. In einer die Erfindung ergänzenden Ausführungsform ist der Lampenträger auf der Garraumwandung in den Garraum weisend angeordnet und weisen seine durch Löcher in der Garraumwandung durchgeführte Anschlußdrähte einen mit der metallischen Garraumwandung geerdete metallische Schirmmantel auf.Preferably, an incandescent lamp for low voltages of at most 30 volts, e.g. to use an incandescent lamp for a connection voltage of 12 volts. In order to achieve high luminous efficacy with small dimensions, the use of halogen lamps is preferred. Incandescent lamps of this type usually also meet the invention, which further improves refinement design criteria, according to which the filament carrier of the lamp and any points on the filament of the incandescent lamp have a maximum distance of 1/16 of the basic microwave frequency radiated into the cooking space. It is also advantageous in a further development of the invention to use an incandescent lamp whose incandescent filament carriers which are guided through the cooking base of the incandescent lamp are designed as terminating plug pins. In an embodiment which supplements the invention, the lamp holder is arranged on the cooking chamber wall pointing into the cooking chamber and its connecting wires, which are led through holes in the cooking chamber wall, have a metallic shielding jacket grounded with the metallic cooking chamber wall.

Üblicher- und zweckmäßigerweise erfolgt die Stromversorgung der Glühlampen aus dem öffentlichen Versorgungsnetz mit den entsprechenden Spannungen, von beispielsweise 220 V. Diese müssen für die erfindungsgemäß verwendeten Lampen mit niederen Spannungs-Anschlußwerten umgeformt werden. Dazu werden bevorzugterweise herkömmliche Transformatoren verwendet, deren ihnen eigene Induktivität den verbleibend geringen durch die Glühlampe aufgenommenen Energien einen praktisch unendlich hohen Widerstand entgegensetzen. Damit wird ein weiterreichender Stromfluß, der durch die Mikrowelleneinstrahlung auf die im Garraum befindliche Glühlampe zurückgeführt werden könnte, durch die Anschlußleitungen für die Glühlampe verhindert.Usually and expediently, the light bulbs are supplied with power from the public supply network with the corresponding voltages, for example 220 V. These have to be converted for the lamps with low voltage connection values used according to the invention. For this purpose, conventional transformers are preferably used, whose inductance of their own opposes the remaining low energy absorbed by the incandescent lamp with a practically infinitely high resistance. This prevents a more extensive flow of current, which could be attributed to the incandescent lamp located in the cooking space due to the microwave radiation, through the connecting lines for the incandescent lamp.

Als mechanischer Schutz gegen unbeabsichtigte Berührungen und Beeinflussungen der Beleuchtungseinrichtung ist die in den Garraum ragende Glühlampe durch eine Glashaube gegenüber dem Garraum abgedeckt.As a mechanical protection against unintentional touching and influencing of the lighting device, the incandescent lamp protruding into the cooking space is covered by a glass hood opposite the cooking space.

Durch die Verwendung einer Glühlampe nach den erfindungsgemäßen Kriterien und insbesondere nach den Kriterien der die Erfindung weiterbildenden Maßnahmen wird eine Beleuchtungseinrichtung geschaffen, die bezüglich der Mikrowellendichtheit des Garraums gegenüber dem Umfeld keinerlei wesentliche Probleme mehr aufwirft. Die Gestaltung und Dimensionierung insbesondere der Glühfadenträger und des Glühfadens gewährleistet, daß die Antennenwirkung der Glühlampe zur Aufnahme der in den Mikrowellenraum eingestrahlten Mikrowellenernergie unerheblich gering ist. Da die Widerstandswerte der Glühdrähte bei Lampen mit niederen Spannungs-Anschlußwerten ebenfalls niedrig sind, können sich etwaig in die Lampenkonstruktion induzierte Ströme unproblematisch auch darin ausgleichen, ohne daß der Glühfaden nachteilig beeinflußt wird. Die Durchführungen durch die Garraumwandung benötigen nunmehr nur den Durchmesser der geschirmten Stromzuführungsanschlüsse, so daß keine Schwierigkeiten zur Herstellung und Gewährleistung der Mikrowellendichtigkeit gegeben sind. Die Anordnung der Glühlampe innerhalb des Garraums ohne ein diese umgebendes metallisches Schirmgitter hat auch den Vorteil, daß die gesamte Leuchtkraft der Glühlampe innerhalb des Garraums zur Verfügung steht. Der Anschlußleistungswert für die Glühlampen kann somit geringer dimensioniert werden und die Verlustleistungen, die sich als abgestrahlte Wärme auswirken, werden gegenüber abgeschirmten Lampen wesentlich reduziert Bei Verwendung von Halogenlampen wird ein helles weißes Licht zur Verfügung gestellt.By using an incandescent lamp according to the criteria according to the invention and in particular according to the criteria of the measures further developing the invention, an illumination device is created which no longer poses any significant problems with regard to the microwave tightness of the cooking chamber with respect to the surroundings. The design and dimensioning, in particular of the filament carrier and of the filament, ensures that the antenna effect of the incandescent lamp for receiving the microwave energy radiated into the microwave space is insignificantly low. Since the resistance values of the filaments in lamps with low voltage connection values are also low, currents which may be induced in the lamp construction can also be balanced out without problems, without the filament being adversely affected. The feedthroughs through the cooking chamber wall now only require the diameter of the shielded power supply connections, so that there are no difficulties in producing and ensuring the microwave tightness. The arrangement of the incandescent lamp within the cooking space without a metallic screen grille surrounding it also has the advantage that the entire luminosity of the incandescent lamp is available within the cooking space. The connected load value for the incandescent lamps can thus be dimensioned smaller and the power losses, which have an effect as radiated heat, are significantly reduced compared to shielded lamps. When using halogen lamps, a bright white light is provided.

Ein nach den Merkmalen der Erfindung ausgestaltetes Ausführungsbeispiel ist anhand der Zeichnung im folgenden näher beschrieben.An embodiment designed according to the features of the invention is described in more detail below with reference to the drawing.

Die Figuren 1 bis 3 zeigen in schematisierten Ansichten an der Garraumwandung angeordnete und in den Garraum hineinragende Beleuchtungseinrichtungen für einen mit Mikrowellenenergie beaufschlagbaren Haushaltsofen in drei verschiedenen Varianten.FIGS. 1 to 3 show, in schematic views, lighting devices arranged in three different variants on the wall of the cooking space and projecting into the cooking space for a domestic oven to which microwave energy can be applied.

Von einem Haushaltsofen mit einem mit Mikrowellenenergie beaufschlagbare Garraum 1,der durch Garraumwandungen und eine Garraumtür allseitig umgeben ist, ist lediglich der die Beleuchtungseinrichtung für den Garraum enthaltende Bereich eines Teilabschnitts 2 einer im Schnitt gezeichneten Garraumwandung dargestellt. Auf diesem Teilabschnitt 2 der Garraumwand ist ein Lampenträger 3 aus elektrisch isolierendem Material befestigt. Von den Steckbuchsen 4 dieses Lampenträgers sind Anschlußleitungen 5 zu einer Stromversorgungseinrichtung, einem nicht dargestellten Transformator geführt. Diese durch die Durchführungsöffnungen 6 durch die Garraumwandung 2 hindurchragenden, isolationsummantelten, Anschlußleitungen 5 tragen im Bereich dieser Durchführungsöffnungen 6 und daran anschließend einen metallischen Abschirmmantel 7, welcher sich auch zwischen dem Lampenträger 3 und der Garraumwandung 2 erstreckt. Dadurch wird eine relevante Abstrahlung von Mikrowellenenergie aus dem Garraum 1 durch die Durchführungslöcher 6 sicher verhindert. Die erforderliche Mikrowellendichtheit in diesem Bereich ist also gegeben. Über dem metallischen Abschirmmantel ist jeweils ein Isolationsrohr 8 übergeschoben.Of a household oven with a cooking space 1 which can be subjected to microwave energy and which is surrounded on all sides by cooking space walls and a cooking space door, only the area of a partial section 2 of a cooking space wall shown in section which contains the lighting device for the cooking space is shown. A lamp holder 3 made of electrically insulating material is attached to this section 2 of the cooking space wall. From the sockets 4 of this lamp holder are connecting lines 5 to a power supply device, not shown Transformer led. These through the through openings 6 through the cooking chamber wall 2, insulated, connecting lines 5 carry in the area of these through openings 6 and then a metallic shielding jacket 7, which also extends between the lamp holder 3 and the cooking chamber wall 2. This reliably prevents relevant radiation of microwave energy from the cooking space 1 through the through holes 6. The required microwave tightness in this area is therefore given. An insulation tube 8 is pushed over the metallic shielding jacket.

In die Steckbuchsen 4 des Lampenträgers 3 sind Anschluß-Steckstifte 10 einer Halogenlampe 11 eingesteckt. Diese Anschlußstifte 10 sind durch den Glassockel 12 der Halogenlampe 11 als im wesentlichen parallel zueinander verlaufende Glühfadenträger 13 weitergeführt. Zwischen den freien Enden der Glühfadenträger 13 innerhalb des Glaskolbens der Halogenlampe 11 ist ein gewendelter Glühfaden 14 gespannt.In the sockets 4 of the lamp holder 3, connector pins 10 of a halogen lamp 11 are inserted. These pins 10 are continued through the glass base 12 of the halogen lamp 11 as an essentially parallel filament carrier 13. A coiled filament 14 is stretched between the free ends of the filament carrier 13 within the glass bulb of the halogen lamp 11.

Der Abstand der Anschluß-Steckstifte und der weitergeführten Glühfadenträger beträgt ca. 4 mm, während die Länge der Glühwendel ca. 6 mm beträgt. Die Anschlußspannung für die Halogenlampe beträgt 12 Volt. Da die Halogenlampe 11 frei in den Garraum ragt, kann eine Anschlußleistung von 5 Watt ausreichend sein.The distance between the connector pins and the continued filament holder is approx. 4 mm, while the length of the filament is approx. 6 mm. The connection voltage for the halogen lamp is 12 volts. Since the halogen lamp 11 projects freely into the cooking space, a connected load of 5 watts may be sufficient.

Die Halogenlampe 11 ist durch eine Glashaube 15 gegenüber dem Garraum 1 abgedeckt, damit ein Schutz gegen ungewolltes Berühren und gegen Beschädigung der Halogenlampe 11 gegeben ist.The halogen lamp 11 is covered by a glass hood 15 opposite the cooking chamber 1, so that protection against unintentional contact and against damage to the halogen lamp 11 is provided.

Die Figuren 2 und 3 zeigen Varianten bezüglich der Anordnung des Lampenträgers 3ʹ und der Glühlampe 11 zur Garraumwandung 2ʹ bzw. 2ʺ, welche in diesem Bereich vom Garraum 1 nach außen eine ggf. ohnehin vorhandene Ausprägung 16ʹ bzw. 16ʺ aufweist. Die Glashaube 15ʹ bzw. 15ʺ ist in dieser Vertiefung der Garraumwandung 2ʹ bzw. 2ʺ unter Anwendung üblicher Maßnahmen lösbar befestigt. Der Lampenträger 3ʹ ist gemäß Fig. 2 auf der dem Garraum 1 zugewandten Seite der Garraumwandung 2ʹ, gemäß Fig. 3 auf der dem Garraum 1 abgewandten Seite der Garraumwandung 2ʺ angeordnet. Im letzteren Fall ragen die Anschlußstifte 10 der Glühlampe 11 durch zwei Löcher 6ʺ der Garraumwandung 2ʺ in den Lampenträger 3ʺ. Die Abschirmung 7ʺ ist an diesem Lampenträger bis zur Garraumwandung 2ʺ herumgezogen.FIGS. 2 and 3 show variants with regard to the arrangement of the lamp holder 3ʹ and the incandescent lamp 11 for the cooking chamber wall 2ʹ or 2ʺ, which in this area has an expression 16ʹ or 16ʺ, which may be present anyway, from the cooking chamber 1. The glass hood 15ʹ or 15ʺ is detachably fastened in this recess of the cooking space wall 2ʹ or 2ʺ using conventional measures. 2 is arranged on the side of the cooking space wall 2ʹ facing the cooking space 1, according to FIG. 3 on the side of the cooking space wall 2ʺ facing away from the cooking space 1. In the latter case, the connecting pins 10 of the light bulb 11 protrude through two holes 6 zwei of the cooking space wall 2ʺ into the lamp holder 3ʺ. The shield 7ʺ is pulled around this lamp holder up to the cooking chamber wall 2ʺ.

Claims (11)

  1. Oven, in particular household oven, with a closed cooking space (1), a microwave generator for the loading of the cooking space (1) with microwaves of a determined fundamental frequency, as well as with an illumination equipment using a bulb (11), which is placed on a lamp carrier (3, 3', 3") supplied with current from outside the cooking space (1) by way of electrical connections, wherein the bulb (11) is arranged projecting freely into the cooking space (1) from the cooking space wall (2, 2', 2") and without electromagnetic screening and has substantially parallelly and adjacently extending bulb filament holders (13) and a bulb filament (14) which is arranged in the glass globe between the ends of the bulb filament carriers (13) and which has a length extension within which all distances between any points of the bulb filament correspond maximally to 10% of the wavelength of the fundamental frequency of the microwaves.
  2. Oven according to claim 1, characterised thereby that the bulb (11) projects into the cooking space (1) from a substantially planar cooking space wall (2).
  3. Oven according to one of the claims 1 or 2, characterised thereby that a low voltage lamp with a connected value of maximally 30 volts is used as bulb (11).
  4. Oven according to claim 3, characterised thereby that a low voltage lamp with a connected value of 12 volts is used as bulb (11).
  5. Oven according to one of the claims 3 or 4, characterised thereby that a halogen lamp is used as bulb (11).
  6. Oven according to one of the claims 3 to 5, characterised thereby that the bulb filament carriers (13) of the bulb (11) and any point of the filament (14) of the bulb (11) have between each maximally a spacing of 1/16 of the fundamental frequency of the microwaves radiated into the cooking space.
  7. Oven according to one of the claims 1 to 6, characterised thereby that a bulb (11) is used of which the bulb filament carriers (13) are formed through the glass socket (12) of the bulb (11) on to connecting plug pins (10).
  8. Oven according to one of the claims 1 to 7, characterised thereby that the lamp carrier (3, 3') is arranged on the cooking space wall (2, 2', 2") at the side of the cooking space and its connecting wires (5) passing through passage holes (6) in the cooking space wall (2) have a screening sleeve (7) earthed with the metallic cooking space wall (2).
  9. Oven according to claim 7, characterised thereby that the lamp carrier (3") is arranged on the side of the cooking space wall (2") which faces away from the cooking space (1) and that the connecting pins (10) of the bulb (11) are plugged into the lamp carrier (3") through passage holes (6") in the cooking space wall (2").
  10. Oven according to one of the claims 1 to 9, characterised thereby that the connections (5) of the illuminating equipment are connected to the current supply by way of an electromagnetic transformer.
  11. Oven according to one of the claims 1 to 10, characterised thereby that the bulb (11) is covered relative to the cooking space (1) by a glass hood (15, 15', 15").
EP87116931A 1986-12-18 1987-11-17 Illuminating arrangement for microwave ovens, in particular for domestic ovens Expired - Lifetime EP0274611B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT87116931T ATE75021T1 (en) 1986-12-18 1987-11-17 LIGHTING DEVICE FOR A MICROWAVE POWERED OVEN, ESPECIALLY A DOMESTIC OVEN.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19863643364 DE3643364A1 (en) 1986-12-18 1986-12-18 LIGHTING DEVICE FOR A STOVE WITH MICROWAVE ENERGY, ESPECIALLY A HOUSEHOLD
DE3643364 1986-12-18

Publications (2)

Publication Number Publication Date
EP0274611A1 EP0274611A1 (en) 1988-07-20
EP0274611B1 true EP0274611B1 (en) 1992-04-15

Family

ID=6316541

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87116931A Expired - Lifetime EP0274611B1 (en) 1986-12-18 1987-11-17 Illuminating arrangement for microwave ovens, in particular for domestic ovens

Country Status (6)

Country Link
US (1) US4814952A (en)
EP (1) EP0274611B1 (en)
JP (1) JPS63163720A (en)
AT (1) ATE75021T1 (en)
DE (2) DE3643364A1 (en)
ES (1) ES2030696T3 (en)

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Publication number Priority date Publication date Assignee Title
DE3830499A1 (en) * 1988-09-08 1990-03-15 Licentia Gmbh Microwave oven having one heating chamber
FR2643829B1 (en) * 1989-03-06 1994-04-01 Prolabo WET CHEMICAL REACTION APPARATUS HAVING A CHIMNEY PROVIDED WITH A MICROWAVE PROPAGATION BARRIER
SE464383B (en) * 1989-07-18 1991-04-15 Whirlpool Int MICROWAVE OVEN WITH A LIGHTING DEVICE FOR INFORMATION OF YOUNG CAVITY
DE4003736A1 (en) * 1990-02-08 1991-08-14 Miele & Cie Microwave oven lighting with truncated conical reflector housing - gives widely scattered distribution of light from filament lamp through transparent screen into irradiated cooking space
JPH0552346A (en) * 1991-08-23 1993-03-02 Matsushita Electric Ind Co Ltd High frequency heating device
JPH0552347A (en) * 1991-08-23 1993-03-02 Matsushita Electric Ind Co Ltd Heating and cooking device
DE9112868U1 (en) * 1991-10-16 1991-12-12 Bosch-Siemens Hausgeräte GmbH, 8000 München Lighting device
US5712468A (en) * 1995-06-01 1998-01-27 Ace; Ronald Microwave oven illumination
DE102015114253B4 (en) * 2015-08-27 2017-06-22 Bjb Gmbh & Co. Kg oven light
SI25187A (en) * 2016-04-20 2017-10-30 Gorenje Gospodinjski Aparati, D.D. A household appliance with electrical component of electromagnetic waves

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DE1589294A1 (en) * 1967-06-19 1970-06-04 Patra Patent Treuhand Halogen light bulbs, especially for motor vehicle headlights
GB1340870A (en) * 1970-12-31 1973-12-19 Electronic Control Surveillanc Lighting unit for use underwater and in wet environments
JPS5421640A (en) * 1977-07-20 1979-02-19 Matsushita Electric Ind Co Ltd High frequency heater
US4140939A (en) * 1978-04-26 1979-02-20 Gte Sylvania Incorporated Tungsten halogen lamp for headlights
US4254450A (en) * 1978-08-21 1981-03-03 General Electric Company Lamp assembly for combination microwave oven and exhaust vent
IT7934007V0 (en) * 1979-02-12 1979-02-12 Zanussi A Spa Industrie LAMP HOLDER, IN PARTICULAR FOR KITCHENS AND OVENS.
NL7909231A (en) * 1979-12-21 1981-07-16 Philips Nv LAMP / REFLEX UNIT.
SE444061B (en) * 1983-03-23 1986-03-17 Philips Norden Ab MICROWAG OVEN LIGHTING DEVICE
DE3606421C1 (en) * 1986-02-27 1987-04-09 Bosch Siemens Hausgeraete Lighting device for a microwave oven
DE8701927U1 (en) * 1987-02-09 1987-04-09 Bosch-Siemens Hausgeräte GmbH, 8000 München Lighting device for a microwave oven

Also Published As

Publication number Publication date
DE3643364C2 (en) 1990-02-15
ES2030696T3 (en) 1992-11-16
DE3643364A1 (en) 1988-07-07
ATE75021T1 (en) 1992-05-15
US4814952A (en) 1989-03-21
JPS63163720A (en) 1988-07-07
DE3778334D1 (en) 1992-05-21
EP0274611A1 (en) 1988-07-20

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