CN114667418A

CN114667418A - Cooking fume extractor with smoke guiding plate and lighting device

Info

Publication number: CN114667418A
Application number: CN202080080200.6A
Authority: CN
Inventors: D·阿贝尔; S·赫特; R·瓦德林格
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2019-11-20
Filing date: 2020-11-04
Publication date: 2022-06-24
Also published as: WO2021099113A1; DE102019217916A1; EP4062106A1

Abstract

The invention relates to a cooking fume extractor having at least one fume guide plate (3) and at least one lighting device (4) comprising at least one light source (410), characterized in that the fume guide plate (3) represents a light guide, the lighting device (4) faces the fume guide plate (3) and a reflection surface (32) is formed on at least one part of an edge (301, 311) of the fume guide plate (3) facing away from the lighting device (4).

Description

Cooking fume extractor with smoke guide plate and lighting device

Technical Field

The present invention relates to a range hood having a smoke guide plate and an illumination device.

Background

For range hoods which are installed above a hob, it is known to arrange a light source on the underside of the range hood in the vicinity of the suction device for illuminating the hob. Furthermore, it is known for so-called underdrain systems, which are installed in the work plate and for which the cooking hood housing projects upwards beyond the work plate on which the hob is installed, to provide a light source on the upper end of the cooking hood housing. The hob is illuminated by the light source, which is mounted, for example, at a height of between approximately 20 and 40 cm.

A disadvantage of such lighting is that on the one hand the light source is directly visible to the user and on the other hand the light source is exposed to the vapors and fumes rising from the hob.

Disclosure of Invention

The object of the present invention is therefore to provide a solution with which a hob or a work surface of a cooking hob can be illuminated with a simple construction of the cooking fume extraction device and which at the same time can eliminate the disadvantages of the prior art.

The recognition on which the invention is based is that this task can be solved by: indirect lighting is performed by means of a part of the cooking fume extractor which performs other functions in addition to lighting.

The object is therefore achieved according to the invention by a cooking fume extraction device having at least one fume guide plate and at least one lighting means comprising at least one light source. The cooking fume extractor is characterized in that the smoke guiding plate represents a light guide, the lighting device faces the smoke guiding plate, and a reflecting surface is formed on at least one part of an edge of the smoke guiding plate, which edge faces away from the lighting device.

The range hood is a device for purifying contaminated air, particularly steam and smoke, generated during cooking. The cooking fume extractor has at least one fume guide plate. The smoke guide means a planar element that guides air sucked by a blower inside the range hood to a suction port of the range hood. The range hood can also be provided with a plurality of smoke guide plates. In particular, an aerosol guide plate can be arranged at the intake opening in front of the intake opening and an aerosol guide plate can be arranged behind the intake opening for forming the transport channel in this way in front of the intake opening in the flow direction. A filter element can be provided inside the range hood or in the suction opening. Through the suction opening, the contaminated air is preferably drawn off downwards.

According to the invention, the at least one smoke guide plate represents a light guide. In particular, the smoke guide plate is made of a material suitable for light conduction. According to one embodiment, the smoke guide plate is made of glass, i.e. is formed by a glass sheet. The surface of the glass pane is preferably polished, so that light introduced into the glass pane via one of the edges is reflected at the surface and is thus further conducted. The aerosol guiding plate can also be referred to as a passive optical waveguide.

A lighting mechanism, which may also be referred to as a lighting module or a lighting device, refers to a device that emits light. The lighting means according to the invention has at least one light source. The light source can represent an LED (light emitting diode). The light source can be arranged on a circuit board. Furthermore, at least the light source can be surrounded by a housing in order to protect it from contamination. The circuit board, on which at least one light source is arranged, can also be received in the housing. The housing is preferably formed in a transparent manner.

According to the invention, the lighting means is directed towards the smoke guide plate. In particular, the lighting device faces an edge of the smoke guide plate, in particular a lower edge of the smoke guide plate. By "towards the smoke guide plate" is meant an orientation of the lighting device along which light emitted from the lighting device can reach the smoke guide plate and in particular the edge of the smoke guide plate directly, i.e. without a deflecting element. In one embodiment, the lighting device can thus rest on an edge of the smoke guide plate or be arranged in the immediate vicinity of the smoke guide plate. However, it is also within the scope of the invention for a distance to be provided between the lighting device and the edge of the smoke guide plate, which edge is oriented towards the lighting device. The edge on which the lighting device is directed is also referred to as the lower or lower edge of the smoke guide plate. The lighting means is directed towards the smoke guide plate, whereby light output by the lighting means can be directed into the smoke guide plate.

Directions such as above and below and directions such as width and height, as long as they are not otherwise specified, relate to a cooking fume extraction device and its components in the installed state. In particular, the description relates to a cooking hob with at least one smoke guide plate in a vertical line, wherein the cooking hob is mounted in a horizontal work plate behind the hob and extends in the width direction of the hob behind the hob.

According to the invention, a reflecting surface is formed on the edge of the smoke guide plate facing away from the lighting device. The reflecting surface can also be referred to as the active surface. The reflecting surface is formed at the lower edge, which is preferably the upper edge of the smoke guide plate. At least a part of the lateral edges of the smoke guide plate can additionally also be designed as a reflective surface.

A reflective surface is formed on the edge of the smoke guide plate facing away from the lighting device, as a result of which the light guided through the smoke guide plate can be directed in a specific direction in a targeted manner. In this way, indirect lighting of, for example, a cooking hob or a work plate can be achieved with the cooking fume extractor according to the invention. Since the smoke guide plate is necessarily provided for guiding steam and smoke to the suction opening of the cooking fume remover without depending on the lighting device, no additional components are required for indirect lighting. Thereby, the structure of the range hood is simplified. Furthermore, the at least one lighting device can be arranged below the work plate, and the light output by the lighting device is guided upwards by the smoke guide plate and output above the work plate. Thereby, the lighting device and the at least one light source arranged therein are not visible to the user. Furthermore, with a possible arrangement of the at least one lighting device below the work plate, it is not possible for the lighting device to be directly impinged upon by steam and smoke and the lighting device is thus protected against contamination.

According to a preferred embodiment, the reflection surface is at an angle of 90 ° relative to the plane of the smoke guide. The surface of the smoke guide plate is a surface of the smoke guide plate which is connected to each other by an edge. The smoke guide plate is preferably arranged before or after the suction opening at the rear of the cooktop and extends in the width direction of the cooktop. The smoke guide plate preferably also extends in the width direction of the hob. Thus, the faces of the smoke guide plate can be referred to as front and back faces. The reflective surfaces are inclined toward these surfaces, so that the light guided upward in the material of the smoke guide plates and between the surfaces is deflected at the upper edge of the smoke guide plates and is guided, in particular, to the work plate or to the hob located upstream of the smoke guide plates and illuminates the hob. Therefore, it is preferable that the reflecting surface is inclined downward at an angle from the front surface of the smoke guide toward the back surface of the smoke guide.

The reflective surface can represent a flat surface. It is also within the scope of the invention and it is preferred that the reflective surface has a curvature. In particular, the reflective surface preferably has a concave curvature. The curvature can be in the width direction of the smoke guide plate. The fixed center of the bending radius can be located behind the smoke guide plate and above the upper edge of the smoke guide plate. By such a curvature of the reflecting surface, light emitted from the reflecting surface can be output in a fan-like manner in the width direction.

According to a preferred embodiment, the reflecting surface has a concave curvature which extends in the height direction of the aerosol guide plate. This means that the reflecting surface of the smoke guide plate has a concave curvature in cross section. Thereby, the light reflected on the reflection surface can fan out in the vertical direction. Thereby, illumination of the cooktop to be illuminated by the illumination device can be ensured in the depth direction.

It is also within the scope of the invention that the concave curvature is present not only in the width direction of the reflective surface but also in its height direction. In this embodiment, the light can be emitted not only in the vertical direction but also in the horizontal direction, fanwise scattered from the reflection surface.

In the embodiment of the reflection surface as a concave surface, the reflection surface is also preferably arranged on the rear side of the smoke guide plate.

The reflective surface can be configured as a polished surface. In this way, the light guided in the smoke guide plate is reflected on the inner side of the reflection surface. The design of the reflection surface as a polished surface has the advantage that the production of the reflection surface is easy and no separate components are required.

According to another embodiment, the reflecting surface can be formed by a coating of a part of the aerosol guiding plate. The reflecting surface is preferably formed by an upper edge of the smoke guide plate which is inclined between the front and the rear of the smoke guide plate. The coating can be applied to the inclined edges of the smoke guide and, if appropriate, to the rear side of the smoke guide. As coating material, for example, metallic coatings, white or black paints are conceivable.

In another embodiment, the reflecting surface is formed by a reflector which is fastened to the smoke guide plate. In particular, the reflector is fastened to an upper edge of the smoke guide plate facing away from the lighting device. The reflector can in particular be a reflector plate, which represents an L-profile.

According to the invention, both in a coated embodiment and in an embodiment with a reflector, the reflecting surface can be provided in addition to the inclination of the edge and/or the curvature of the edge.

The smoke guide plate is made of a light guiding material. In particular, the smoke guide plate can be made of glass, Plexiglas (Plexiglas) or other light-conducting plastic.

In one embodiment, an optical element for introducing light via the edge of the smoke plate facing the lighting device is arranged between the lighting device and the smoke guide plate. The optical element can for example represent a lens or a diffuser plate. The edge of the smoke guide plate facing the lighting device can have a polished or matt, in particular roughened surface. By the arrangement of the optical elements, in particular lenses, it can be ensured that light is guided in a targeted manner from the illumination device into the smoke guide plate.

According to a preferred embodiment, the cooking fume removal device has a suction opening through which air is sucked in downward and the at least one fume guide is arranged adjacent to the suction opening. In such embodiments, the invention can also be referred to as a table top vent, a trough vent, or a lower row vent. In this embodiment, the design of the aerosol guiding plate as a light guide according to the invention can be used particularly well. In particular, the smoke guide plate can be used as a design element or as a functional lamp by means of light introduction from the lighting device.

According to one embodiment, two smoke guide plates are provided and a reflective surface is formed only on one of the smoke guide plates and the other smoke guide plate is frosted, in particular roughened, at least on the edge facing away from the lighting device. In this embodiment, one of the smoke guide plates is preferably arranged between the hob and the suction opening, and the other smoke guide plate is arranged behind the suction opening. The rear fume guide can in this embodiment have a greater height than the front fume guide. In the embodiment with two smoke guide plates, the rear smoke guide plate preferably has a reflective surface on the upper edge. As a result, the cooktop in front of the smoke guide can be illuminated well due to the usually greater height of the smoke guide. On the front fume guide, a reflective surface can also be formed on the upper edge and the hob can therefore also be illuminated by this fume guide. However, it is also within the meaning of the invention that the upper edge of the front smoke guide plate is sanded and in particular roughened. The light guided upwards by the smoke guide plate can thus be scattered out of the edge.

Drawings

The present invention will be described again with reference to the accompanying drawings. Wherein:

fig. 1 shows a schematic perspective view of an embodiment of the inventive cooking fume extraction device;

fig. 2 shows a further schematic perspective view of the embodiment of the cooking fume extraction device according to the invention according to fig. 1;

fig. 3 shows a schematic sectional view of an embodiment of the inventive cooking fume extraction device in the region of the fume guide plate;

fig. 4 shows a schematic sectional view of an embodiment of the cooking device according to the invention in the region of a lighting device;

fig. 5 shows a schematic sectional view of a further embodiment of the cooking hood according to the invention in the region of a lighting device;

figure 6 shows a schematic, schematic sketch of an aerosol guide plate with a lighting device;

fig. 7 and 8 show schematic views of the light paths at the upper and lower edges of the smoke guide plate;

figure 9 shows a schematic sketch of a smoke guide plate with a lighting device; and is provided with

Fig. 10 and 11 show schematic views of the light paths at the upper and lower edges of the smoke guide plate.

Detailed Description

Fig. 1 shows a perspective view of an embodiment of the inventive cooking fume extraction device 1. The cooking fume extraction device 1 is arranged behind the cooking hob 5 in the work plate 6. The cooking fume extraction device 1 has a cooking fume extraction housing 2, in which only the upper side can be seen in fig. 1. In the hood casing 2, a suction port 20 is provided in the upper side surface. Through this suction opening 20, steam and fumes generated when cooking on the cooking hob 5 can be sucked into the cooking fume extracting apparatus 1. For this purpose, the cooking fume extraction device 1 has a blower, which is not shown in the figures.

In the embodiment shown in fig. 1, the cooking fume extraction device 1 has two fume guide plates 3. In particular, a smoke guide plate 3 is provided in front of the intake opening 20, i.e. between the intake opening 30 and the hob 5 and behind the intake opening 20. The smoke guide 3 is in the vertical line and represents a flat plate, in particular a glass plate. The smoke guide plate 3 extends in the width direction of the cooking hood 1, that is, in the width direction of the cooktop 5. The front aerosol guide plate 30 has a smaller width and a smaller height than the rear aerosol guide plate 31. Below the intake opening 20, an illumination device (not visible in fig. 1) is arranged in the cooking hood 1 and in particular in the cooking hood housing 2, by means of which illumination device light can be guided into the smoke guide plate 3.

Fig. 2 shows the situation in the state in which the lighting device is activated, i.e. switched on, according to the embodiment of the cooking fume extraction device 1 from fig. 1. In this state, the light guided upwards by the trailing louver guide 31 is deflected at the upper edge 31 of the trailing louver guide 31. This diverted light is output forward. In particular, the light is output in this case at a downward inclination. Thereby, the cooktop 5 can be illuminated by the light. In the embodiment shown, the front smoke guide plate 30 is not illuminated. However, it is also within the scope of the invention for the upper edge 301 of the front smoke guide plate 30 to also output light obliquely forwards and downwards. Alternatively, ambient light can be output from the front louver guide 30, and/or the upper edge 301 of the front louver guide 30 and, if applicable, the upper region of the lateral edge of the front louver guide 30 can be illuminated.

Fig. 3 shows a sectional view of an embodiment of the cooking hood 1 in the region of the smoke guide 3. In this embodiment, the smoke guide plates 30, 31 are each in the vertical. The

lower edges

300, 310 of the front and rear smoke guide plates 30, 31 are each directed toward the luminaire 4. A reflecting surface 32 is formed on the upper edge 311 of the rear smoke guide plate 31. For this purpose, the rear side of the upper edge 311 is beveled and serves as a reflector. As shown in fig. 3, the upwardly directed light is deflected in the smoke guide plate 31 by the reflection surface 32 and is output obliquely forward and downward.

Fig. 4 and 5 show possible embodiments of the cooking fume extraction device 1 in the area of the lighting device 4. In each of these embodiments, a lighting device 4 is formed, which has an optical element 42 mounted thereon or integrated in the lighting device 4. The lighting devices 4 each have a light-emitting unit 41. The lighting unit 41 comprises at least one circuit board and at least one light source 410, such as an LED, applied to the circuit board. The light source 410 is directed upwards.

In the embodiment according to fig. 4, the lighting device is clipped into a mounting plate of a cooking hood housing, in which the smoke guide plates 30, 31 are accommodated. The smoke guide 30 can be supported separately in the hood housing. In the embodiment according to fig. 4, a diffuser plate 421 is provided as an optical element 42 on or in the upper side of the lower edge 300 of the front-facing smoke guide plate 30 of the lighting device 4. The diffusing plate can guide light from the lighting device 4 into the front smoke guide 30 in a diffused manner. On or in the upper side of the lower edge 310 of the rearward-facing smoke guide plate 31 of the lighting device 4, a lens 420 is provided as an optical element 42. By means of this lens 420, light can be directed into the rear aerosol guide plate 31. In the embodiment of fig. 4, the front and rear louver plates 30, 31 are each placed directly on the respective optical element 42 with their

lower edges

300, 310. The upper side of the optical element 42 is adapted to the shape of the

lower edges

300, 310.

The embodiment according to fig. 5 differs from the embodiment according to fig. 4 in that an intermediate lens 43, which can also be referred to as an intermediate profile, is arranged between the optical element 42 and the

lower edges

300, 310 of the respective smoke guide plates 30, 31. In this embodiment, the central lens 43 has a shape on its upper side that is matched to the

lower edges

300, 310. The lower side of the central lens 43 is flat and rests on the likewise flat upper side of the optical element 42. In the embodiment according to fig. 5, the intermediate lens serves as a sealing element and as a protective element. The lighting device 4 is in this embodiment located below the support plate.

Different embodiments of the light introduction and light output of the smoke-guide plate 3 will now be described with reference to figures 6, 7 and 8. The smoke guide plate 3 is referred to as the rear smoke guide plate 31 here, which is shown in fig. 1 to 5. However, the smoke guide 3 can also be the front smoke guide 30.

In the schematic sketch of fig. 6, a plurality of light sources are shown below the lower edge of the smoke guide plate. The width of the smoke guide plate can be 600mm, for example. The height of the smoke guide plate can be 320mm, for example, and the thickness can be 6mm, for example. The material of the smoke guide can be ESG (single layer safety glass) white glass. As is evident from the side view of the aerosol guide on the left in fig. 6, a reflective surface is provided on the upper edge on the rear side of the aerosol guide.

Fig. 7a to 7e show different designs of the upper edge region of the smoke guide plate 31. In fig. 7a, the upper edge has an edge angle on the rear side as a reflection surface, which can be, for example, a 5 × 35 ° edge angle. The surface of the corner is polished. In fig. 7b, the reflecting surface on the upper edge of the smoke guide plate is designed as a concave corner. The surface of the corner is polished. In fig. 7c, the reflecting surface on the upper edge of the smoke guide is designed as a concave corner and its surface is polished. In the embodiment according to fig. 7c, a reflector is additionally arranged on the upper edge. The reflector is in particular adhered to the smoke guide plate. The reflector can be a reflective plate. In the illustrated embodiment, the reflective plate has an L-shape. One leg is here on the upper side of the smoke guide and the second leg is on the back side of the smoke guide. In fig. 7d, the reflecting surface on the upper edge of the smoke guide plate is likewise embodied as a concave edge with a polished surface. Furthermore, in this embodiment, paint is applied not only to the upper side of the aerosol guide plate but also to the corner. The paint can be a black paint or a white paint. The embodiment according to fig. 7e corresponds to the embodiment according to fig. 7 d. However, in this embodiment, the underside of the aerosol guide plate is also painted, in addition to the corners and the upper side.

As is evident from fig. 7a to 7e, the design of the reflection surfaces can divert the beam path of the light and, if necessary, fan it out.

Fig. 8a to 8b show a design of the lower edge of the smoke guide plate. In the embodiment of fig. 8a, the lower edge of the aerosol guide plate is designed as a C-ground surface and has a polished surface. This embodiment can be used in all embodiments according to fig. 7a to 7e of the upper edge of the smoke guide plate. The embodiment of fig. 7b differs from the embodiment of fig. 7a only in that paint is applied to the back of the aerosol guide plate. This embodiment is particularly suitable for the embodiment according to fig. 7e of the upper edge, in which case the entire rear side of the aerosol guide plate can be painted.

The embodiments of the upper and lower edges of the smoke guide plate of fig. 7 and 8 can be used in particular for generating operating light, in particular for illuminating cooktops.

Different embodiments of the light introduction and light output of the aerosol guiding plate 3 will now be described with reference to figures 9, 10 and 11. The smoke guide 3 is referred to here as the front smoke guide 30, which is shown in fig. 1 to 5. However, the smoke guide 3 can also be the rear smoke guide 31.

In the schematic sketch of fig. 9, a plurality of light sources are shown below the lower edge of the smoke guide plate. The width of the smoke guide plate can be, for example, 480 mm. The height of the aerosol guide plate can be 220mm, for example, and the thickness can be 6mm, for example. The material of the smoke guide plate can be ESG (single layer safety glass) white glass. In the embodiment shown, no reflective surface is provided on the rear side of the air deflector at the upper edge, as is indicated by the side view of the air deflector on the left in fig. 9.

Fig. 10a to 10c show different designs of the upper edge region of the smoke guide plate 30. In fig. 10a, the upper edge has the shape of a C-ground surface with a polished surface. In fig. 10b, the upper edge has the shape of a C-ground surface with a matt surface. In fig. 10C, the upper edge has the shape of a C-ground surface with a matt surface, and the back of the aerosol guide plate is painted. The paint can be a white paint or a black paint.

Fig. 11a to 11c show a design of the lower edge of the smoke guide plate. In the embodiment of fig. 11a, the lower edge of the aerosol guide plate is designed as a C-ground surface and has a polished surface. This embodiment can be used in particular for the embodiment according to fig. 10a of the upper edge of the smoke guide plate. The embodiment of fig. 11b differs from the embodiment of fig. 11a in that the lower edge is matt. This embodiment can be used in particular for the embodiment according to 10b of the upper edge of the smoke guide plate. The embodiment of fig. 11c differs from the embodiment according to fig. 11b only in that the aerosol guide plate is painted on the rear side.

The embodiments of the upper and lower edges of the smoke guide plates of fig. 10 and 11 can be used in particular for generating background light.

The cooking bench can be illuminated by the oil fume extraction device. The illumination is performed by the cooking hood mounted in the work plate on elements of the passive light guide, in particular the smoke guide plate, via the reflection surface, which can also be referred to as the optical active surface. Furthermore, with the invention it is possible to design such an illumination scheme of the hob to be as bright and uniform as possible.

In the present invention, for the so-called bottom-discharge type cooking fume extractor, the range is illuminated by: in the area below the work plate, which cannot be seen directly by the user, the light is guided into a smoke guide plate, which is embodied as a light guide, which is guided back to the top of the hob on the reflective surface of the light guide above the hob. In this case, the light-guiding edge of the smoke guide plate can be formed as a reflector.

The exact geometry of the reflecting surface, which can also be referred to as reflecting element, is selected such that as much light as possible reaches the cooking surface. Furthermore, glare is minimized for the user.

Furthermore, it is conceivable to make the light guide as resistant as possible to grease and dirt deposits by means of a specific coating method (lotus effect). This prevents or minimizes stray light coupled out at undesired locations.

One advantage of the invention is that it can be operated with pure glass or glass with a coated/frosted surface, optionally also with a material similar to glass, such as plexiglas (Plaxiglas) or similar. A further advantage of the invention is the concealment of the light source.

When positioned below the work plate, the light source is furthermore protected against influences on the hob.

A further advantage is that the smoke guide plate of the light guide, which is preferably made of glass, can be removed and cleaned or replaced without depending on the light source and its current supply. A direct mechanical connection between the lighting means and the smoke guide plate is not necessary.

List of reference numerals:

1 oil fume extractor

2 oil smoke exhausting casing

20 suction inlet

3 Smoke guide plate

30 front smoke guide plate

300 lower edge

301 upper edge

Smoke guide plate behind 31

310 lower edge

311 upper edge

32 reflective surface

4 Lighting device

41 light emitting unit

410 light source

42 optical element

420 lens

421 diffusing plate

43 intermediate lens

5 cooking bench

6 working plate.

Claims

1. A cooking fume extraction device having at least one fume guide plate (3) and at least one illumination device (4) comprising at least one light source (410), characterized in that the fume guide plate (3) represents a light guide, the illumination device (4) facing the fume guide plate (3) and forming a reflection surface (32) on at least one portion of an edge (301, 311) of the fume guide plate (3) facing away from the illumination device (4).

2. A cooking fume extraction device according to claim 1, wherein the reflecting surface (32) is at an angle other than 90 ° with respect to the plane of the fume guide (3).

3. A cooking fume extraction device according to claim 2, wherein the reflective surface (32) represents a flat surface.

4. The cooking fume extraction device according to any one of claims 1 or 2, wherein said reflecting surface (32) has a concave shape extending along the width direction of said fume guide plate (3) and/or along the height direction of said fume guide plate (3).

5. The cooking fume extraction apparatus according to any one of claims 1 to 4, wherein the reflective surface (32) is configured as a polished surface.

6. The cooking fume extraction device according to any one of claims 1 to 5, wherein the reflective surface (32) is formed by a coating of a portion of the fume guide plate (3).

7. The cooking fume extraction device according to any one of claims 1 to 6, wherein the reflective surface (32) is formed by a reflector fixed on the fume guide plate (3).

8. The fume extraction device according to any of claims 1 to 7, wherein said fume guide plate (3) is made of glass.

9. The cooking fume extraction device according to any one of claims 1 to 8, wherein an optical element (42) for introducing light through an edge (300, 310) of the fume guide plate (3) facing the lighting device (4) is arranged between the lighting device (4) and the fume guide plate (3).

10. The cooking fume extraction device according to any one of claims 1 to 9, wherein the cooking fume extraction device (1) has a suction opening (20) through which air is drawn downwards and the at least one fume guide plate (3) is arranged adjacent to the suction opening (20).

11. The cooking fume extraction device according to any one of claims 1 to 10, wherein two fume guide plates (3) are provided and the reflecting surface (32) is formed on only one of said fume guide plates (31), and the other fume guide plate (30) is frosted at least on the edge (301) facing away from the lighting means (4).