EP4224067A1 - Cooking appliance with cooking chamber and camera for observing the cooking chamber - Google Patents

Abstract

The present invention relates to a cooking appliance (1) with a housing and a cooking space (3) arranged in the housing, the cooking space (3) being delimited by cooking space walls (4.1, 4.2, 4.3, 4.4), the housing outside the cooking space (3) a camera (15) for observing the cooking chamber (3) is arranged, with a first viewing window (9.1) between the camera (15) and the cooking chamber (4.1, 4.2, 4.3, 4.4) being 3) is embedded, wherein the first viewing window (9.1) has cooling on a side facing away from the cooking chamber (3), characterized in that the first viewing window (9.1) is formed by a transparent substrate (20) and one on the substrate (20) catalytic layer (21, 23) applied on the cooking chamber side for decomposing organic impurities, the catalytic layer (21, 23) being formed in a transparent layer thickness (d). With this cooking appliance (1), an improved view for the camera (15) can advantageously be achieved.

Description

technical field

The invention relates to a cooking appliance with a housing and a cooking chamber arranged in the housing, the cooking chamber being delimited by the cooking chamber walls, a camera for observing the cooking chamber being arranged in the housing outside the cooking chamber, with a first viewing window in a first region of the cooking chamber walls is let in between the camera and the cooking chamber, and wherein the first viewing window has cooling on a side facing away from the cooking chamber. In particular, the cooking appliance is designed as a baking oven with a pyrolysis function.

Background of the Invention

Cooking devices such as ovens, in which viewing windows are embedded in the cooking chamber walls, are already known. On the one hand, it is well known that with such cooking appliances, viewing windows are provided in a mostly vertical front, in particular in a cooking chamber door, through which a person using the cooking appliance can look, for example to observe or check the cooking process of an item to be cooked. Furthermore, it is also known that viewing windows are arranged in the cooking chamber walls between the cooking chamber and a camera, for example in a horizontal cooking chamber ceiling delimiting the cooking chamber at the top. Such a camera is used, for example, as a sensor for controlling the cooking appliance, such as automatic shutdown depending on the degree of cooking detected by the camera or automatic browning of the food and/or allows a person using the cooking chamber from a distance via a terminal to observe.

In the aforementioned cooking devices, the cooling in the area of the camera ensures that temperatures are lower than those in the cooking chamber to prevent damage to the camera. The cooling also results in a reduced temperature on the side of the first viewing window facing the cooking chamber compared to the rest of the cooking chamber, which disadvantageously does not reach a sufficient decomposition temperature for organic impurities in certain operating states of the cooking appliance and causes these impurities to polymerize on the first viewing window, so that a contamination that can only be removed with great effort comes from the first viewing window. In particular, such contamination occurs during pyrolytic cleaning of the cooking appliance with very high temperatures of over 400° C. in the cooking chamber, during which sufficient decomposition temperatures for the organic contaminants are not reached at the first viewing window due to the reduced temperatures. The soiling then impedes the free view of the camera through the first viewing window, so that controlling the cooking appliance using the camera and/or observing the food to be cooked on a terminal is disrupted. In particular, even to a small extent, such contamination can cause distortions in a color spectrum coming through the first viewing window, which impedes control of the cooking appliance by the camera.

Out of US 2018/0073741 A1 a baking oven is known in which a coating with hydrophilic and/or lipophilic properties is applied to the walls of the cooking space in order to collect impurities in the area of these coatings and to reduce them in other areas of the baking oven. The cleaning of the oven can then be reduced to the areas of the coatings. In some embodiments, the coating is combined with a catalytic coating and a heating layer to remove accumulated contaminants.

Furthermore, transparent photocatalytic coatings for various technical applications are known from the prior art, such as from EP 1 585 658 A1 , JP 2000-131747 A or U.S. 2014/319491 A1 .

Description of the invention

Proceeding from the background of the invention, it is an object of the present invention to ensure an improved view for the camera in a described cooking appliance.

The object of the invention is solved by the features of the independent main claims. Advantageous configurations are specified in the dependent claims. As far as technically possible, the teachings of the subclaims can be combined with the teachings of the main and subclaims in any way.

In particular, the object is therefore achieved by a cooking appliance as described above, in which the first viewing window is formed by a transparent substrate and a catalytic layer applied to the substrate on the cooking chamber side for decomposing organic impurities, the catalytic layer being formed with a transparent layer thickness.

Advantageous aspects of the claimed invention are explained below and preferred modified embodiments of the invention are further described below. Explanations, in particular on advantages and definitions of features, are basically descriptive and preferred, but not limiting, examples. If an explanation is limiting, this is expressly mentioned.

If elements are identified by numbering, for example "first component", "second component" and "third component", this numbering is intended purely for differentiation in the designation and does not represent any interdependence of the elements from one another or a mandatory order of the elements This means in particular that a device does not have to have a “first component” in order to be able to have a “second component”. The device can also include a “first component” and a “third component”, but without necessarily having a “second component”. Several units of an element of a single numbering can also be provided, ie for example several "first components".

A cooking appliance is designed in particular as an oven in which, for example, temperatures of approximately 100-250° C. are provided in the cooking chamber for the preparation of food. The cooking appliance also preferably has a pyrolysis function, in which the temperature in the cooking chamber is increased to up to 500° C., so that organic impurities present on the cooking chamber walls are decomposed and detached from the cooking chamber walls. Organic contamination occurs when cooking food, in particular from fats and oils that are released from the food and settle on the walls of the cooking space. The cooking appliance can also be designed as an oven with an integrated microwave.

The cooking chamber of the cooking appliance is preferably designed as a cavity in the housing that is insulated against an outer wall of the cooking appliance by means of thermal insulation. The cooking space can preferably be filled with food to be cooked via an opening or such food to be cooked can be removed from the cooking space via the opening. Means for heating the air in the cooking chamber and means for circulating the air in the cooking chamber are preferably provided in or on the cooking chamber. In particular, air ducts and/or air baffles are also provided in the cooking chamber or in the walls of the cooking chamber, the geometry of which influences the air flow in the oven. The term air is also used here in the sense of vapors located in the cooking chamber, for example when food to be cooked is located in the cooking chamber and corresponding substances and steam are emitted into the air. Furthermore, means for radiating heat can be provided in the cooking chamber.

The first viewing window is sealed in particular with respect to the wall of the cooking space in which it is embedded, so that no air from the cooking space can get past the first viewing window into the area of the camera. The camera is preferably located above the food to be cooked, ie above an upper cooking space wall extending in a horizontal plane, and is directed downwards at the food to be cooked. Such a positioning allows a particularly good view of the food to be cooked. Insofar as the first viewing window has cooling, this can only be cooling for the first viewing window or cooling that also cools other areas or components around the camera and/or the camera itself. In particular, the cooling is designed as air cooling, with cooled air circulating around the camera in an air volume adjacent to the first viewing window, so that the cooled air flows along the side of the first viewing window facing away from the cooking chamber. Alternatively, the cooling can also be liquid cooling. The first viewing window can also be designed as a part of a multiple pane on the cooking chamber side, with a coolant flowing along in the spaces between the panes.

The above solution to the problem now includes the teaching that the first viewing window has a catalytic layer. By means of such a catalytic layer, it is possible to reduce the decomposition temperature of organic impurities located on the first viewing window. In this way, the organic contaminants at the first viewing window are decomposed more easily, in particular even at temperatures at which the contaminants would polymerize without a catalytic layer. In particular, there is no polymerization of the contaminants during pyrolytic cleaning of the cooking appliance with cooking chamber temperatures above 400° C. and the organic contaminants deposited on the first viewing window are instead decomposed. The first viewing window is therefore only soiled to a reduced extent, so that an improved view for the camera can be achieved, in particular even after a large number of use and/or cleaning cycles. In this case, the catalytic layer is formed in a transparent layer thickness and therefore particularly advantageously has no relevant influence on the view through the first viewing window. Such a transparent layer thickness can be selected depending on the material or materials used for the catalytic layer. A layer thickness in which the catalytic layer produces a sufficient catalytic effect while remaining transparent can be achieved with materials that have a sufficient Have temperature resistance, in particular for the temperatures prevailing in the cooking chamber during a pyrolysis cleaning.

In a preferred embodiment, the cooking appliance has an opening for filling the cooking chamber and at least one cooking chamber door for closing the opening, the cooking chamber door forming a cooking chamber wall, a second viewing window being embedded in the cooking chamber door, and the second viewing window being covered by a transparent substrate and a catalytic layer applied to the substrate on the cooking chamber side for decomposing organic impurities is formed, the catalytic layer being formed in a transparent layer thickness. In particular, the catalytic layer on the second viewing window can be formed in the same manner and from the same material or materials as the catalytic layer on the first viewing window. Contamination by organic impurities also occurs on the surface of the second viewing window on the cooking chamber side. In particular, contamination can also occur on the second viewing window in a manner similar to that on the first viewing window as a result of polymerization of organic contaminants, since the second viewing window is in contact with an environment of the cooking appliance on a side facing away from the cooking chamber and, depending on the air temperature in this environment, on the Cooking chamber side of the second viewing window can be present in relation to the rest of the cooking chamber reduced temperature. The catalytic layer on the second viewing window achieves the same advantages as the catalytic layer on the first viewing window, so that dirt on the second viewing window is reduced or avoided and the view through the second viewing window, for example for a person standing in front of the garrum door is improved.

In one configuration of this embodiment, the second viewing window has cooling on a side facing away from the cooking chamber. In this case, the temperatures on the cooking chamber side of the second viewing window are particularly reduced compared to the rest of the cooking chamber, so that the problem of the polymerization of organic impurities is particularly high consists. In this configuration, the catalytic layer therefore achieves particularly great advantages in that contamination is avoided. The cooling of the second viewing window can, for example, be in the form of air or liquid cooling. In particular, the second viewing window is designed as a part of a multiple pane on the cooking chamber side, with a coolant flowing along in the spaces between the panes.

In a particularly preferred form, the catalytic layer of the first viewing window and/or the second viewing window has at least one platinum metal, in particular platinum, palladium, iridium and/or ruthenium. A very good catalytic effect is already achieved with thin layer thicknesses by means of such platinum metals, so that the catalytic layer can be applied to the substrate sufficiently thinly to be transparent. Furthermore, platinum metals have a particularly high thermal stability, so that there is no risk of damage to the catalytic layer even when carrying out pyrolysis cleaning at temperatures between 400° C. and 500° C.

Furthermore, the catalytic layer of the first viewing window and/or the second viewing window preferably has at least one metal oxide, in particular copper oxide, magnesium oxide and/or manganese oxide. A very good catalytic effect is also achieved with such metal oxides even with thin layer thicknesses, so that the catalytic layer can be applied to the substrate sufficiently thinly to be transparent. Furthermore, metal oxides have a particularly high thermal stability, so that there is no risk of damage to the catalytic layer even when pyrolysis cleaning is carried out at temperatures between 400° C. and 500° C.

The catalytic layer preferably has a plurality of substances, in particular at least one platinum metal and at least one metal oxide, in order to set particularly favorable catalytic properties for a specific temperature range.

In one embodiment, the layer thickness of the catalytic layer of the first viewing window and/or the second viewing window is between 80 nanometers and 1500 nanometers, preferably between 130 nanometers and 1300 nanometers, in particular greater than 16 nanometers and/or less than 1100 nanometers. With such a layer thickness, depending on the material or materials used for the catalytic layer, a sufficient catalytic effect to avoid contamination can be achieved, with the catalytic layer being transparent. The layer thickness is preferably chosen to be as thick as possible with existing transparency in order to make the catalytic layer as durable as possible.

In a preferred embodiment, the catalytic layer of the first viewing window and/or the second viewing window is applied by a spraying method, an immersion method, an ALD method, a PVD method, a CVD method and/or a sputtering method. By the methods mentioned, a catalytic layer can be formed in each case with a transparent layer thickness and sufficiently adhering to the substrate. ALD stands for "atomic layer deposition" and describes a process for the deposition of extremely thin layers, up to atomic monolayers, on a starting material. PVD stands for "physical vapor deposition" and describes a vacuum-based process in which the material for the catalytic layer is converted into the gas phase and condenses on the substrate to form the catalytic layer. CVD stands for "chemical vapor deposition" and describes a process in which the catalytic layer is deposited on a heated surface of the substrate as a result of a chemical reaction from the gas phase. In the sputtering process, atoms are released from a solid body by bombardment with high-energy ions and go into the gas phase. The sputtering process can be used in particular in connection with the PVD process for converting the material for the catalytic layer into the gas phase.

In a further preferred embodiment, at least one of the first viewing window and the second viewing window between the substrate and the catalytic layer on a support layer. Such a carrier layer is particularly preferably designed as a porous layer or a frit for receiving the catalytic layer and can serve, for example, to increase the binding force between the catalytic layer and the substrate. The support layer can also serve to provide a framework for the catalytic layer such that the surface area of the catalytic layer is increased for improved mass transfer. The catalytic layer, even if it is applied to the carrier layer, is understood to be applied to the substrate. The carrier layer particularly preferably has at least one silicon oxide, such as a silicon dioxide. The carrier layer can optionally be applied to the substrate in a coating process that precedes the coating with the catalytic layer, or the carrier layer and the catalytic layer are applied to the substrate simultaneously in a common coating process. In one embodiment, in which it is applied to the substrate before the catalytic layer is applied, the carrier layer is particularly preferably burned in before the catalytic layer is applied to the substrate. A particularly good bond between the carrier layer and the substrate is achieved by baking. Insofar as the support layer and the catalytic layer are applied together, they can also form a combined layer that performs the function of a support layer and the function of the catalytic layer. A combined layer is understood on the one hand as a catalytic layer applied to the substrate and on the other hand as a carrier layer arranged between the catalytic layer and the substrate.

In a further preferred embodiment, the substrate of the first viewing window and/or the second viewing window is made of glass. For use as a substrate, glass offers the particular advantages that it is transparent, has good thermal stability and is chemically inert to the catalytic layer and/or the carrier layer.

Furthermore, the solution described above includes the teaching that the ceramic layer has a lipophobic property. The ceramic layer thus forms a large contact angle with oils and/or fats, so that such substances cannot be deposited on the first viewing window. This advantageously ensures that no organic impurities are deposited on the viewing window, which would impair the view through the viewing window. The first viewing window thus remains free of dirt and condensation, so that overall a significantly improved view through the viewing window is made possible.

A lipophobic property of the ceramic layer can be achieved, for example, by combining different ceramics in the ceramic layer and thus forming a combined layer. Ceramic particles can also be embedded in another material or other materials, for example in a matrix of another material or other materials, with a combined layer also being formed. Furthermore, a lipophobic property can also be achieved, for example, by additional structuring or chemical treatment of the surfaces of the ceramic layer.

In one embodiment, the cooking appliance has an opening for filling the cooking chamber and at least one cooking chamber door for closing the opening, the cooking chamber door forming a cooking chamber wall and the first viewing window being embedded in the cooking chamber door. The first viewing window is used in particular for a person standing in front of the cooking appliance to observe the cooking space, for example to check the degree of cooking of the food. Furthermore, a camera for observing the cooking chamber can also be arranged in front of a first viewing window let into the cooking chamber door and outside the housing, for example for controlling the cooking appliance and/or for observing the cooking chamber from a distance via a terminal. The above-described formation of the first viewing window with a ceramic layer then achieves the advantage that the person standing in front of the cooking appliance or the camera positioned in front of the first viewing pane has as free a view of the cooking chamber as possible at all times or have the food to be cooked therein, with the first viewing window remaining free of condensation and/or dirt.

In an embodiment in which the cooking chamber door, and accordingly also the first viewing window, extend in a vertical plane, the hydrophilic ceramic oxide coating described above also achieves the advantage that no drops form on the first viewing window that run down the first viewing window and meet a seal at a lower end. Instead, a layer of water forms on the first viewing window, which has a more favorable surface-to-volume ratio compared to the droplets and thus promotes rapid mass transport of the liquid back into the vapor phase. In this respect, there is no need for a liquid-tight seal with respect to the environment in the lower area of the first viewing window in order to prevent liquid from escaping from the cooking appliance. It is therefore possible to use seals that are suitable for higher temperatures but are only vapor-tight.

The object is also achieved by a cooking appliance with a housing and a cooking chamber arranged in the housing, the cooking chamber being delimited by the walls of the cooking chamber, a camera for monitoring the cooking chamber being arranged in the housing outside the cooking chamber, with the Cooking chamber walls a first viewing window is let in between the camera and the cooking chamber, the first viewing window being formed by a transparent substrate and a hydrophilic ceramic layer applied to the substrate on the cooking chamber side, and the ceramic layer being formed in a transparent layer thickness.

Such a cooking appliance has the advantages already described above with regard to the relevant features. In particular, the cooking device for a camera located inside the housing has the advantage that water deposited on the first viewing window forms a small contact angle and thus a thin layer of water is created, which produces less refraction than water droplets that would otherwise form. The water thus forms no fogging on the first viewing window, as already described above with regard to the first solution, and the view through the first viewing window is not fogged up or prevented by such a fogging. The camera is preferably arranged above the cooking chamber, with the first viewing window being embedded in a cooking chamber wall delimiting the cooking chamber at the top and extending in a horizontal plane. By avoiding condensation on the first viewing window, ie the formation of fine droplets, it is advantageously avoided that such droplets detach from the surface of the first viewing window and drip onto the food to be cooked.

In one embodiment, the ceramic layer of the first viewing window also has a previously described lipophobic property, so that no dirt can accumulate on the first viewing window.

In a preferred embodiment of one of the solutions to the problem described above, a second viewing window is embedded in the cooking appliance in a second area of the cooking chamber walls, the second viewing window being formed by a transparent substrate and a hydrophilic ceramic layer applied to the substrate on the cooking chamber side, and the ceramic layer is formed in a transparent layer thickness. The second viewing window then also has the above-described advantageous properties when water is deposited and remains untarnished.

In one configuration of this embodiment with at least one camera arranged outside the cooking chamber for observing the cooking chamber, an opening for filling the cooking chamber and at least one cooking chamber door for closing the opening, with the cooking chamber door forming a cooking chamber wall, the first viewing window is between the camera and the cooking chamber embedded in a cooking chamber wall and the second viewing window embedded in the cooking chamber door. An improved view is achieved both for the viewing window in the door and for the viewing window through which the camera observes the cooking space or the food to be cooked.

In a preferred embodiment, the ceramic layer of the second viewing window also has a previously described lipophobic property, so that no dirt can accumulate on the second viewing window.

In one embodiment of one of the solutions described above, in which the cooking appliance has a cooking chamber door, the cooking appliance has a door seal for sealing the opening closed by the cooking chamber door from the surroundings of the cooking appliance, the door seal being made in particular of glass silk. Such a seal prevents steam and/or liquid from escaping from the cooking chamber into the vicinity of the cooking appliance at the door. A door seal made of glass fiber also has the advantage that it can withstand high temperatures in the cooking chamber, such as those that occur during pyrolytic cleaning, without showing any damage or leaks.

In a further embodiment of one of the aforementioned solutions, the ceramic layer of the first viewing window and/or the second viewing window is formed as a ceramic oxide layer, for example with silicon nitride, titanium dioxide and/or aluminum oxide. These ceramic oxides make it possible to achieve advantageously favorable hydrophilic properties with layer thicknesses that are transparent and temperature-resistant, even at the temperatures required for pyrolysis cleaning, and have a good longevity. The hydrophilic properties can thus be achieved with the materials mentioned even with such thin layer thicknesses that the ceramic oxide layer can be applied to the substrate in a sufficiently thin manner to be transparent. The ceramic oxide layer can also have a plurality of materials, in particular in order to form a lipophobic property in addition to a hydrophilic property. For this purpose, for example, the ceramic oxide is embedded in a different material.

In another embodiment of one of the aforementioned solutions, the ceramic layer of the first viewing window and/or the second viewing window is designed as a non-oxide ceramic layer, for example with silicon carbide, silicon nitride, titanium nitride.

In one embodiment, the layer thickness of the ceramic layer of the first viewing window and/or the second viewing window is between 50 nanometers and 1500 nanometers, preferably between 150 nanometers and 1200 nanometers, in particular more than 200 nanometers and/or less than 1000 nanometers. With such a layer thickness, depending on the material or materials used for the ceramic layer, a sufficient hydrophilic effect can be achieved to avoid fogging on the viewing window and the ceramic layer is transparent. A lipophobic property can also be favorably developed with such a layer thickness. The layer thickness is preferably selected to be as thick as possible with existing transparency in order to make the ceramic layer as durable as possible.

In a further embodiment, the ceramic layer of the first viewing window and/or the second viewing window forms a contact angle of less than 15° with water. The ceramic layer of the first viewing window and/or the second viewing window particularly preferably forms a contact angle of less than 12° with water. With such a contact angle, a sufficiently low degree of light refraction is achieved in a viewing window wetted with water, so that the view through the window is not impeded by the water layer or only to an acceptable extent.

In another preferred embodiment, the ceramic layer of the first viewing window and/or the second viewing window is applied by a sol-gel process, a PVD process, a CVD process and/or a PECVD process. In a sol-gel process, the ceramic layer is made from colloidal dispersions. PVD stands for "physical vapor deposition" and describes a vacuum-based process in which the material for the ceramic layer is converted into the gas phase and condenses on the substrate to form the ceramic layer. CVD stands for "chemical vapor deposition" and describes a process in which the ceramic layer is deposited on a heated surface of the substrate as a result of a chemical reaction from the gas phase. A PECVD corresponds to a CVD process, where the preceding PE stands for "plasma enhanced" stands and points out that in such a CVD process the chemical reaction is enhanced by a plasma.

In one embodiment, at least one of the first viewing window and the second viewing window has a structuring of the surface on the cooking chamber side. A hydrophilic and/or a lipophobic property of the ceramic can be further improved by means of such a structuring. For example
For example, the contact angle that water makes on the surface can be reduced, or the contact angle that a fat or oil makes on the surface can be increased. The surface is structured, for example, by a laser-based method or a chemical method.

The object is also achieved by a viewing window for a cooking appliance as described above, having a transparent substrate and a hydrophilic ceramic layer applied to the substrate, the ceramic layer being formed with a transparent layer thickness and the ceramic layer having a lipophobic property. The advantages described above with regard to a cooking appliance are correspondingly achieved with such a viewing window.

Brief description of the drawings

The invention is explained in more detail below with reference to the accompanying drawings using preferred exemplary embodiments. The wording figure is abbreviated to figure in the drawings.

Show in the drawings

Fig. 1a

a schematic sectional view through a cooking appliance according to one aspect of the invention;

Fig. 1b

a snippet Fig. 1a ;

1c

another snippet Fig. 1a ;

Figure 2a

a schematic representation of a viewing window for a cooking appliance according to an aspect of the invention in a first embodiment;

Figure 2b

a schematic representation of a viewing window for a cooking appliance according to an aspect of the invention in a second embodiment; and

Figure 2c

a schematic representation of a viewing window for a cooking appliance according to an aspect of the invention in a third embodiment.

Detailed description of the exemplary embodiments

The exemplary embodiments described are merely examples that can be modified and/or supplemented in a variety of ways within the scope of the claims. Each feature described for a particular embodiment can be used on its own or in combination with other features in any other embodiment. Each feature that is described for an embodiment of a certain category of claims can also be used in a corresponding manner in an embodiment of another category of claims.

Figure 1a shows a cooking appliance 1 designed as an oven with a housing (not shown) and a cooking chamber 3 arranged in the housing. The cooking chamber 3 is through a first cooking chamber wall 4.1 on an upper side, through a second cooking chamber wall 4.2 on a lower side, and on a front side a third cooking chamber wall 4.3 and bounded on a rear side by a fourth cooking chamber wall 4.4, the cooking chamber 3 being further bounded by cooking chamber walls, not shown, on a right side and on a left side. In the cooking chamber 3 there is a food support 5 on which the food 6 rests. The cooking chamber walls 4.1, 4.2, 4.4 can be insulated from the housing in a manner that is not shown.

The third cooking chamber wall 4.3 is formed by a cooking chamber door 7, wherein the cooking chamber door 7 can be swung open in order to open or close an opening 8 in the cooking chamber 3. The cooking chamber door 7 has a handle 7.1 and a second viewing window 9.2 embedded in it, the second viewing window 9.2 being designed as the inner of three panes of multiple glazing and being sealed against the door 7 by means of a seal 10.

A camera 15 is arranged above and outside the cooking chamber 3, which is surrounded by a cooling air volume 16 in which, for example, compressed cooling air from a compressor (not shown) circulates, as indicated by two arrows. The cooling air can be cooled with means that are not shown, such as a heat exchanger and/or a heat pump. A first viewing window 9.1 is embedded in the first cooking chamber wall 4.1 between the camera 15 and the cooking chamber 3, the first viewing window 9.1 being able to be sealed off from the first cooking chamber wall 4.1 by means of a seal (not shown). The first viewing window 9.1 borders the cooking chamber 3 with one cooking chamber side and the cooling air volume 16 with a side facing away from the cooking chamber 3. The camera 15 is directed downwards and observes the food to be cooked 6 located in the cooking chamber 3 through the first viewing window 9.1, as with a viewing cone of the camera 15 indicated.

Figure 1b is a detail view Figure 1a , in which the area around the camera 15 is shown. It can be seen here that the first viewing window 9.1 is formed by a transparent substrate 20 and a catalytic layer 21 applied thereto. The catalytic layer 21 extends over the entire first viewing window 9.1 and brings about a reduced decomposition temperature for organic impurities adhering to the first viewing window 9.1. In this way, such organic contaminants are already decomposed at temperatures at which polymerization would otherwise occur and, as a result, soiling of the first viewing window 9.1 that would be difficult to clean would take place. In the same way as in Figure 1b the first viewing window is shown in Figure 1c a detailed view Figure 1a shown, which shows the cooking chamber door 7 . Here it can be seen that the second viewing window 9.2 also consists of a Substrate 20 and a catalytic layer 21 applied to the substrate is formed.

The Figures 2a to 2c show different embodiments of the first viewing window 9.1 and/or the second viewing window 9.2 in a side section. These each have a substrate 20, the substrate 20 being transparent. For example, the substrate 20 is made of glass. In a first embodiment Figure 2a a catalytic layer 21 is applied to the substrate, the catalytic layer 21 having a transparent layer thickness d. The catalytic layer 21 is formed, for example, from a material containing a platinum metal and/or a metal oxide. In a second embodiment Figure 2b a carrier layer 22 is applied to the substrate, the carrier layer 22 having a silicon oxide, for example, and being formed in a transparent layer thickness. On the carrier layer in turn a catalytic layer 21 is applied in a transparent layer thickness d, which corresponds to the catalytic layer 21 after Figure 2a can be trained. In a third embodiment Figure 2c a combined layer 23 consisting of a carrier material and a catalytic material introduced on or in the carrier material is applied to the substrate.

Reference List

1

cooking appliance

3

cooking chamber

4.1

first cooking chamber wall

4.2

second cooking chamber wall

4.3

third cooking chamber wall

4.4

fourth cooking chamber wall

5

food carrier

6

food

7

cooking chamber door

7.1

Cooking compartment door handle

8th

opening

9.1

first viewing window

9.2

second viewing window

10

poetry

15

camera

16

cooling air volume

20

substrate

21

catalytic layer

22

backing layer

23

combined layer

i.e

layer thickness

Claims (16)

Cooking appliance (1) with a housing and a cooking space (3) arranged in the housing, the cooking space (3) being delimited by cooking space walls (4.1, 4.2, 4.3, 4.4), with a camera in the housing outside the cooking space (3). (15) is arranged for observing the cooking chamber (3), a first viewing window (9.1) being embedded between the camera (15) and the cooking chamber (3) in a first area of the cooking chamber walls (4.1, 4.2, 4.3, 4.4), the first viewing window (9.1) having cooling on a side facing away from the cooking chamber (3), characterized in that the first viewing window (9.1) is covered by a transparent substrate (20) and a catalytic layer ( 21, 23) for decomposing organic impurities, wherein the catalytic layer (21, 23) is formed in a transparent layer thickness (d). Cooking appliance (1) according to one of the preceding claims, having an opening (8) for filling the cooking chamber (3) and at least one cooking chamber door (7) for closing the opening (8), the cooking chamber door (7) forming a cooking chamber wall (4.3). , wherein a second viewing window (9.2) is embedded in the cooking chamber door (7), and wherein the second viewing window (9.2) is covered by a transparent substrate (20) and a catalytic layer (21, 23) applied to the substrate (20) on the cooking chamber side for Decomposition of organic impurities is formed, wherein the catalytic layer (21, 23) is formed in a transparent layer thickness (d). Cooking appliance (1) according to one of the preceding claims, wherein the second viewing window (9.2) has cooling on a side facing away from the cooking chamber (3). Cooking appliance (1) according to one of the preceding claims, wherein the catalytic layer is formed as a hydrophilic ceramic layer (21) and/or as a lipophobic ceramic layer (21). Cooking appliance (1) according to one of the preceding claims, wherein the catalytic layer (21, 23) of the first viewing window (9.1) and/or the second viewing window (9.2) has at least one platinum metal, in particular platinum, palladium, iridium and/or ruthenium. Cooking appliance (1) according to one of the preceding claims, wherein the layer (21) applied to the first viewing window (9.1) and/or second viewing window (9.2) on the cooking chamber side is designed as a hydrophilic ceramic layer (21) with a transparent layer thickness (d). Cooking appliance (1) according to one of the preceding claims, wherein a first viewing window (9.1) let into a cooking space wall (4.1) between the camera (15) and the cooking space (3) extends in a horizontal plane. Cooking appliance (1) according to one of the preceding claims, wherein a first viewing window (9.2) or second viewing window (9.2) embedded in the cooking chamber door (7) extends in a vertical plane. Cooking appliance (1) according to one of the preceding claims, wherein the layer (21, 23) of the first viewing window (9.1) and/or the second viewing window (9.2) contains at least one metal oxide, in particular a ceramic oxide, for example copper oxide and/or magnesium oxide and /or manganese oxide and/or zirconium oxide and/or titanium dioxide and/or aluminum oxide. Cooking appliance (1) according to one of the preceding claims, wherein the layer thickness (d) of the catalytic layer (21, 23) of the first viewing window (9.1) and/or the second viewing window (9.2) is between 80 nanometers and 1500 nanometers. Cooking appliance (1) according to one of the preceding claims, wherein the catalytic layer (21, 23) of the first viewing window (9.1) and / or the second viewing window (9.2) by a spraying method, an immersion method, an ALD method, a PVD method , a CVD process and/or a sputtering process is applied. Cooking appliance (1) according to one of the preceding claims, wherein at least one of the first viewing window (9.1) and the second viewing window (9.2) has a carrier layer (22) between the substrate (20) and the catalytic layer (21, 23), in particular a porous layer or frit for containing the catalytic layer (21, 23). Cooking appliance (1) according to Claim 8, in which the carrier layer (22) has at least one silicon oxide. Cooking appliance (1) according to one of the preceding claims, wherein at least one of the first viewing window (9.1, 9.2) and the second viewing window (9.2) has a structuring of the surface on the cooking chamber side. Cooking appliance (1) according to one of the preceding claims, wherein the substrate (20) of the first viewing window (9.1) and/or the second viewing window (9.2) is formed from glass. Cooking appliance (1) according to one of the preceding claims, designed as a baking oven, in particular as a baking oven with a pyrolysis function.

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