Patent Description:
Various different types of cooking appliance are known, such as table-top cooking appliances that are positionable by the consumer on a table-top or kitchen countertop.

One type of table-top cooking appliance is the air fryer. Air fryers are already common kitchen appliances but their popularity continues to grow. Air fryers may, for example, take the form of portable ovens which are designed to fit on a kitchen work surface.

Air fryers can be distinguished from conventional convection ovens at least partly by the direction of air circulation through the cooking chamber. The air fryer's cooking chamber has, when orientated for use, a top and a bottom. Referring to an air fryer of <CIT>, a circulation system, e.g. in the form of a fan driven by a motor, is arranged to circulate air upwardly through food received in the cooking chamber in the direction of the top and/or downwardly through food received in the cooking chamber in the direction of the bottom.

By, for instance, mounting the air fryer's heating element proximal to the top of cooking chamber, air having passed upwardly through the food can be reheated by the heating element before being passed around a duct and being introduced back into the food at the bottom. Such an arrangement has various advantages, particularly in terms of the frying effect which can be achieved with no or only a relatively small amount of cooking oil being required.

Another type of table-top cooking appliance is the so-called air cooker, whose circulation system may be arranged to circulate air laterally, e.g. horizontally, across and through food received in the cooking chamber, with the air being laterally directed towards a side portion of the cooking chamber.

Including an image sensor in a cooking appliance, such as an air fryer or air cooker, can play an important role in smart assisted cooking. For example, referring to an air fryer of <CIT>, a food type can be recognized by food image recognition and a cooking setting can be determined based on food image analysis. Moreover, food images can be used for cooking process control, browning control, remote monitoring, burning prevention, and content for social media sharing. <CIT> is another example of cooking appliance comprising a cooking chamber, a heating element, a viewing window and an image sensor arranged to enable image capture of food received in the cooking chamber through the viewing window.

Other applications of image sensors in cooking appliances include capturing images and/or video for identification of food amount, e.g. volume, food distribution within the cooking chamber, and doneness level.

However, the relatively rapid airflow in cooking appliances having circulation systems, and in air fryers in particular, together with aerosols generated during cooking, can cause rapid pollution of a viewing window, in other words viewport, through which the image sensor captures images of the food received in the cooking chamber.

Such pollution can mean that algorithms, e.g. trained algorithms, employed to derive the above-mentioned food-related information from image(s) of the food may be unable to function reliably. In the worst case, the viewing window may be polluted to such an extent that even capturing an image of the cooking chamber through the viewing window is precluded.

One possible option for removing pollution from the viewing window is pyrolytic cleaning. However, this relies on exposing the viewing window to relatively high temperatures which may not be attainable using the heating system of typical cooking appliances, and especially table-top cooking appliances, such as air fryers and air cookers. Moreover, such high temperatures could risk damaging the image sensor.

Other potential solutions, such as detachably mounting the viewing window to facilitate cleaning and/or replacement of the viewing window, may be inconvenient for the user and costly to implement.

According to examples in accordance with an aspect of the invention, there is provided a cooking appliance comprising: a cooking chamber; a heating element; a viewing window; an image sensor arranged to enable image capture of food received in the cooking chamber through the viewing window; a circulation system arranged to circulate air heated by the heating element in the cooking chamber; and a flow guiding element arranged in a path of an airflow provided by the circulation system in a direction of the viewing window, the flow guiding element comprising a ramp arranged to displace at least part of the airflow away from the viewing window and guide said at least part of the airflow across the viewing window.

By the ramp of the flow guiding element redirecting the airflow away from the viewing window, e.g. from a plane of the viewing window, pollution of the viewing window by, in particular, aerosols generated during cooking of the food received in the cooking chamber can be alleviated. Moreover, since the airflow displaced from the viewing window is nonetheless guided by the ramp across the viewing window, the flow guiding element may provide minimal disruption to heated air circulation in the cooking chamber, and therefore may exert minimal influence over cooking of the food received in the cooking chamber.

The term "plane of the viewing window" as used herein may refer to a plane of a planar surface of the viewing window, e.g. that is exposed to the interior of the cooking chamber. Alternatively, the term "plane of the viewing window" may refer to a plane that is tangential to a non-planar surface of the viewing window, e.g. that is exposed to the interior of the cooking chamber.

Such a tangential plane may, for example, extend perpendicular to a normal extending through a center of the viewing window.

Thus, the term "plane of the viewing window" is not intended to refer only to planar viewing windows. In some embodiments, the viewing window is non-planar, e.g. having a non-planar surface.

Examples of non-planar viewing windows may include viewing windows having a curved contour, e.g. a convex surface.

Such a non-planar viewing window may, for example, be a lens, e.g. provided in addition to a lens included in the image sensor arranged behind the viewing window.

It is generally noted that the airflow may be provided along an interior surface delimiting, or arranged within, the cooking chamber.

In other words, the airflow may be a surface airflow provided along such an interior surface.

In some embodiments, the interior surface is included in a surface of the cooking chamber wall that delimits the cooking chamber. Alternatively, the interior surface may be included in a surface of a partition wall arranged in the cooking chamber.

In some embodiments, the flow guiding element comprises a protrusion that protrudes from the interior surface along which the airflow is provided.

Such a protrusion may provide a relatively straightforward and effective way of implementing the flow guiding element, for example relative to alternative solutions involving a ramp-comprising recess defined in the interior surface.

In some embodiments, the protrusion extends at least partly around the viewing window, for example with the ramp also extending at least partly around the viewing window.

In such embodiments, the protrusion may displace air flowing from various directions towards the viewing window away from the plane of the viewing window, and across the viewing window.

The protrusion may, for example, delimit a hole, e.g. a frustroconical hole, through which light passes to reach the viewing window.

In some embodiments, the protrusion is detachable from the interior surface.

This may assist with cleaning the viewing window (as well as the protrusion itself), particularly in embodiments in which the protrusion extends at least partly around the viewing window.

In some embodiments, the ramp extends in the direction of the viewing window to a point that is spaced apart from the viewing window along an axis extending normal to the viewing window. Thus, the ramp may extend to a height that is different from that of the plane of the viewing window, thereby facilitating displacement of the airflow away from the plane of the viewing window and across the viewing window.

The flow guiding element may comprise a defined edge at which extension of the ramp in the direction of the viewing window terminates. Such a defined, e.g. sharp, edge may assist to ensure that the airflow initially guided up the ramp is directed by the flow guiding element across, rather than back towards, the viewing window.

In some embodiments, the flow guiding element is arranged to guide a portion of the airflow, e.g. passing along the interior surface, laterally around the viewing window.

Such lateral guiding of the airflow around the viewing window may assist to minimize disruption caused by the flow guiding element to heated air circulation in the cooking chamber, and may thus assist to minimize the flow guiding element's influence over cooking of the food received in the cooking chamber.

In some embodiments, the flow guiding element comprises sides that face in directions transverse to the airflow, with one or both of the sides being connected to a base of the ramp via a curved portion that curvedly extends from the ramp around to the respective side.

Such curved portion(s) may assist the flow guiding element to guide a portion of the airflow laterally around the viewing window.

In some embodiments, the viewing window is arranged in a cooking chamber wall that at least partly delimits the cooking chamber. Alternatively, the viewing window may be arranged in the partition wall located within the cooking chamber.

In embodiments in which the cooking appliance comprises the partition wall, and irrespective of whether or not the viewing window is arranged in the partition wall, an inner surface of the partition wall may at least partly delimit an inner cooking chamber arranged within the cooking chamber.

A duct may be defined between the cooking chamber wall that at least partly delimits the cooking chamber and an outer surface of the partition wall.

In such embodiments, the circulation system may be arranged to circulate at least part of the heated air around the duct, into and through the inner cooking chamber, and back into the duct, with the duct being arranged to fluidly connect a top and a bottom of the inner cooking chamber to each other such that the circulating at least part of the heated air passing through the inner cooking chamber traverses a height of the inner cooking chamber.

By the heated air passing through the inner cooking chamber traversing a height of the inner cooking chamber, the heated air may be delivered through food received in the inner cooking chamber. This may assist to achieve frying-type cooking effect.

In some embodiments, an air guide member is arranged to guide the at least part of the heated air circulated by the circulation system into the inner cooking chamber, and along the inner surface of the partition wall in the direction of the viewing window.

In such embodiments, the air guide member may be arranged in the duct. Thus, the air guide member may assist to guide the at least part of the heated air from the duct into the inner cooking chamber.

The air guide member, for example a star fish-type air guide member, may assist to provide the airflow along the interior surface in the direction of the viewing window.

In some embodiments, the air guide member is arranged to guide the airflow along the interior surface, e.g. the inner surface of the partition wall.

In such embodiments, the air guide member may be arranged to provide a rotational component to the airflow, such that the path of the airflow winds around the interior surface. This rotational component may be provided in addition to the airflow's traversing of the height of the inner cooking chamber.

More generally, the cooking chamber and the circulation system may be arranged such that, when the cooking appliance is orientated for use, at least part of the heated air traverses a height of the cooking chamber.

It is noted that upward and/or downward heated airflow through the cooking chamber may not require the partition wall, the inner cooking chamber and the duct described above. Thus, in some embodiments the partition wall, the inner cooking chamber and the duct may be omitted.

For example, instead of the partition wall, the inner cooking chamber and the duct, the cooking appliance may include a perforate food supporting base, e.g. a mesh or grid plate, arranged or arrangeable inside the cooking chamber for supporting food. In such embodiments, mass heated air circulation within the cooking chamber may be provided, with both upward and downward airflow directions through the cooking chamber being possible.

The cooking chamber may be at least partly delimited by a base portion, a top portion, and a side portion extending between the base portion and the top portion. It is noted that the terms "base" and "top" in this context may refer to an in-use orientation of the cooking appliance, for example when the cooking appliance is positioned on a kitchen table or countertop, with the base portion being proximal to the kitchen table or countertop, the top portion being distal with respect to the kitchen table or countertop, and the side portion upstanding from the base portion in the direction of the top portion.

In some embodiment, the viewing window is arranged in or proximal to the top portion. Such positioning of the viewing window may facilitate capturing of images of the food received in the cooking chamber.

The flow guiding element may be arranged at or proximal to the top portion.

For example, the flow guiding element and the viewing window may both be arranged at or proximal to the top portion.

Thus, the flow guiding element may be arranged to minimize pollution of the viewing window arranged in or proximal to the top portion.

It is noted that the term "proximal to" in this context may mean that the relevant component, e.g. the flow guiding element and/or the viewing window, is arranged at/in the side portion but closer to the top portion than to the base portion.

In some embodiments, the ramp slopes from the top portion downwardly towards the base portion. Airflow may therefore be guided downwardly by the ramp towards the base portion of the cooking chamber, and thus away from the viewing window, e.g. away from the viewing window arranged in the top portion.

In some embodiments, the top portion comprises a heat reflector. Such a heat reflector may, among other things, assist to protect the image sensor from the heat within the cooking chamber when the viewing window is arranged in the heat reflector and/or in an upper part of the side portion.

In some embodiments, the cooking appliance comprises a seal around the viewing window for restricting fluid passage around the viewing window towards the image sensor.

Such a seal may assist to minimize the risk of damage to the image sensor, for example by hot air and/or steam passing between the cooking chamber wall, or the partition wall, and the viewing window.

In at least some embodiments, the cooking appliance comprises at least one light emitter arranged to illuminate at least part of the cooking chamber through the viewing window and/or through a further window arranged adjacent to the viewing window.

In embodiments in which the cooking appliance comprises the further window, the ramp of the flow guiding element may be arranged to displace at least part of the airflow away from the further window, e.g. a plane of the further viewing window, and guide the at least part of the airflow across the further window.

In such embodiments, the alleviation of pollution of the viewing window and/or the further window by the flow guiding element may also assist to minimize disruption to illumination of the cooking chamber provided by the light emitter(s).

More generally, the cooking appliance may be a domestic cooking appliance, for example a domestic cooking appliance in the form of a table-top cooking appliance.

The cooking appliance, e.g. domestic cooking appliance, may be an oven.

Such an oven may, for example, be a table-top oven or a built-in type oven for installation in a kitchen.

In some embodiments, the cooking appliance is an air fryer or an air cooker.

It is noted that the air fryer and the air cooker may be examples of table-top cooking appliances.

When the cooking appliance is an air fryer, the circulation system may be arranged to circulate air upwardly through food received in the cooking chamber in the direction of the top portion and/or downwardly through food received in the cooking chamber in the direction of the base portion.

When the cooking appliance is an air cooker, the circulation system may be arranged to circulate air laterally across and through food received in the cooking chamber, with the air being laterally directed towards the side portion.

Provided is a cooking appliance comprising a cooking chamber, a heating element, and a circulation system arranged to circulate air heated by the heating element in the cooking chamber. The circulation system provides an airflow within the cooking chamber, e.g. along an interior surface delimiting, or arranged within, the cooking chamber. The cooking appliance further comprises a viewing window towards which the airflow is directed, and an image sensor arranged to enable image capture of food received in the cooking chamber through the viewing window. A flow guiding element is arranged in a path of the airflow. The flow guiding element comprises a ramp arranged to displace at least part of the airflow away from the viewing window, e.g. away from a plane of the viewing window, and guide the at least part of the airflow across the viewing window.

<FIG> schematically depicts a cooking appliance <NUM> according to an example. The cooking appliance <NUM> in this example is in the form of an air fryer. However, the present disclosure is more generally applicable to any type of cooking appliance <NUM>.

Particular mention is made of the cooking appliance <NUM> being a domestic cooking appliance <NUM>, for example a domestic cooking appliance <NUM> in the form of a table-top cooking appliance <NUM>.

In some embodiments, the cooking appliance <NUM> is an air cooker. It is noted that the air fryer and the air cooker may be examples of table-top cooking appliances <NUM>.

The cooking appliance <NUM> comprises a cooking chamber <NUM> in which food (not visible) is receivable. The cooking chamber <NUM> may be at least partly delimited by a cooking chamber wall <NUM>.

The cooking chamber <NUM> may be at least partly delimited by a base portion 103A, a top portion 103B, and a side portion 103C extending between the base portion 103A and the top portion 103B. The base portion 103A, the top portion 103B, and the side portion 103C may be included in, e.g. may define, the cooking chamber wall <NUM>.

It is noted that the terms "base" and "top" in this context may refer to an in-use orientation of the cooking appliance <NUM>, as shown in <FIG>. Such an in-use orientation may be adopted, for example, when the cooking appliance <NUM> is positioned on a kitchen table or countertop, with the base portion 103A being proximal to the kitchen table or countertop, the top portion 103B being distal with respect to the kitchen table or countertop, and the side portion 103C upstanding from the base portion 103A in the direction of the top portion 103B.

In some embodiments, such as shown in <FIG>, the cooking appliance <NUM> includes a partition wall <NUM> whose inner surface at least partly delimits an inner cooking chamber <NUM> arranged within the cooking chamber <NUM>. In such embodiments, food may be received specifically within the inner cooking chamber <NUM>.

In some embodiments, the top portion 103B comprises a heat reflector. Such a heat reflector may, among other things, assist to protect sensitive components of the cooking appliance <NUM>, such as control circuitry, from the heat within the cooking chamber <NUM>.

The heat reflector may be formed from any suitable material, such as a metal or metal alloy, e.g. steel. The heat reflector is preferably formed from galvanized plate metal.

The cooking appliance <NUM> comprises a viewing window <NUM>, whose function will be explained in more detail herein below. In some embodiments, such as shown in <FIG>, the viewing window <NUM> is arranged in the cooking chamber wall <NUM>. For example, the viewing window <NUM> may be arranged in, or at least proximal to, the top portion 103B.

In alternative embodiments, such as shown in <FIG> and <FIG>, the viewing window <NUM> is arranged in the partition wall <NUM>, subject, of course, to the cooking appliance <NUM> including such a partition wall <NUM>.

In embodiments in which the cooking appliance <NUM> includes the partition wall <NUM>, a duct <NUM> may be defined between the cooking chamber wall <NUM> and an outer surface of the partition wall <NUM>. Heated air may be circulated around the duct <NUM>, into and through the inner cooking chamber <NUM>, and back into the duct <NUM>.

In such embodiments, the duct <NUM> may be arranged to fluidly connect a top and a bottom of the inner cooking chamber <NUM> to each other such that the circulating heated air passing through the inner cooking chamber <NUM> traverses a height of the inner cooking chamber <NUM>.

To this end, one or more apertures 107A may be provided in a bottom of the inner cooking chamber <NUM>, with one or more openings 107B being provided in the top of the inner cooking chamber <NUM>. In such embodiments, the duct <NUM> may provide a fluid connection between the opening(s) 107B and the aperture(s) 107A that extends around the outer surface of the partition wall <NUM>.

In such embodiments, the aperture(s) 107A may be defined by apertures of a perforate food supporting base. The perforate food supporting base may be regarded as a platform on which food for cooking/baking/frying/steaming may be supported.

In some embodiments, the cooking appliance <NUM> comprises a basket whose bottom portion corresponds to the perforate food supporting base.

More generally, the cooking chamber <NUM> may be arranged such that, when the cooking appliance <NUM> is orientated for use, at least part of the heated air traverses a height of the cooking chamber <NUM>.

The traversing of the height of the cooking chamber <NUM> may mean that the at least part of the heated air passes upwardly and/or downwardly through the cooking chamber <NUM>.

In other words, this traversing of the height of the cooking chamber <NUM> may mean upward and/or downward heated airflow through the food received in the cooking chamber <NUM>. This may assist to provide the frying effect provided by the cooking appliance <NUM>, e.g. air fryer.

It is noted that such upward and/or downward heated airflow through the cooking chamber <NUM> may not require the partition wall <NUM>, the inner cooking chamber <NUM> and the duct <NUM> described above. Thus, in some embodiments the partition wall <NUM>, the inner cooking chamber <NUM> and the duct <NUM> may be omitted.

For example, instead of the partition wall <NUM>, the inner cooking chamber <NUM> and the duct <NUM>, the cooking appliance <NUM> may include a perforate food supporting base, e.g. a mesh or grid plate, arranged or arrangeable inside the cooking chamber <NUM> for supporting food. In such embodiments, mass heated air circulation within the cooking chamber <NUM> may be provided, with both upward and downward airflow directions through the cooking chamber <NUM> being possible.

The cooking appliance <NUM> comprises an image sensor <NUM> arranged to enable image capture of food received in the cooking chamber <NUM>, e.g. received in the inner cooking chamber <NUM> in the case of the non-limiting examples shown in <FIG>, <FIG> and <FIG>, through the viewing window <NUM>.

Such image capture may enable identification of a food type, amount, distribution and/or doneness level of the food received in the cooking chamber <NUM>, e.g. in the inner cooking chamber <NUM>.

Such identification may be implemented via image analysis performed by a processing system included in the cooking appliance <NUM> and/or in a processing system included in a cloud-based server and/or in an external user device, such as a smartphone or tablet computer, separate from the cooking appliance <NUM>.

Any suitable type of image sensor <NUM> may be contemplated, for example a charge coupled device (CCD) image sensor <NUM> or a complementary metal-oxide-semiconductor (CMOS) image sensor <NUM>.

In at least some embodiments, the viewing window <NUM> is formed of a suitable optically transmissive/transparent and thermally robust material.

The viewing window <NUM> may be made of glass.

Such a viewing window <NUM>, e.g. a glass window <NUM>, arranged between the cooking chamber <NUM>, e.g. the inner cooking chamber <NUM>, and the image sensor <NUM> may assist to protect the image sensor <NUM> from cooking conditions in the cooking chamber <NUM>.

In some embodiments, the cooking appliance <NUM> comprises a seal around the viewing window <NUM> for restricting fluid passage around the viewing window <NUM> towards the image sensor <NUM>.

Such a seal may assist to minimize the risk of damage to the image sensor <NUM>, for example by hot air and/or steam passing between the cooking chamber wall <NUM>, or the partition wall <NUM>, and the viewing window <NUM>.

In embodiments, such as shown in <FIG>, in which the cooking appliance <NUM> includes the partition wall <NUM>, the inner cooking chamber <NUM> and the duct <NUM>, the image sensor <NUM> and the viewing window <NUM> may be arranged so that the image sensor <NUM> can capture images of the inner cooking chamber <NUM> through the duct <NUM>.

To this end, a gap may be defined in the partition wall <NUM>, through which gap the image sensor <NUM> can capture images of the inner cooking chamber <NUM>.

In at least some embodiments, and referring to <FIG>, the cooking appliance <NUM> comprises at least one light emitter arranged to illuminate at least part of the cooking chamber <NUM>, e.g. the inner cooking chamber <NUM>, through the viewing window <NUM> and/or through a further window <NUM>.

Any suitable type of light emitter can be contemplated. In at least some embodiments, the at least one light emitter comprises one or more light emitting diodes.

In embodiments, such as shown in <FIG>, in which the cooking appliance <NUM> includes the further window <NUM>, the further window <NUM> may be arranged adjacent to the viewing window <NUM>.

The viewing window <NUM> may be regarded as being included in, e.g. may be defined by, a transparent plate. Alternatively, the viewing window <NUM> may be included in a window assembly comprising a plurality of transparent elements.

In embodiments in which the cooking appliance <NUM> comprises the further window <NUM>, the further window <NUM> and the viewing window <NUM> may, for example, correspond to respective transparent elements included in such a window assembly. An example of this is shown in <FIG>.

In some embodiments, the image sensor <NUM> and the viewing window <NUM> may be included, e.g. together with the light emitter(s) and/or the further window <NUM>, if present, in a camera assembly CA.

Such a camera assembly CA may facilitate mounting of the image sensor <NUM> and the viewing window <NUM> in the cooking appliance <NUM>, since the camera assembly CA may define the spatial relationship between the image sensor <NUM> and the viewing window <NUM> prior to the camera assembly CA being positioned in the cooking appliance <NUM>.

More generally, the cooking appliance <NUM> includes a heating element <NUM>, and a circulation system <NUM>, <NUM> arranged to circulate air heated by the heating element <NUM> in the cooking chamber <NUM>.

The heating element <NUM> can have any suitable design. In some embodiments, the heating element <NUM> comprises a resistive heating element <NUM>. Particular mention is made of a spiral resistive heating element <NUM>.

Air can, for example, be circulated by the circulation system <NUM>, <NUM> through space(s) between coils of such a spiral resistive heating element <NUM> in order to heat the air. Such coils are schematically depicted in <FIG>, <FIG>, <FIG> and <FIG>.

In at least some embodiments, the circulation system <NUM>, <NUM> comprises a fan <NUM> and a motor <NUM>, with rotation of the fan <NUM> by the motor <NUM> causing the circulating of air.

In some embodiments, such as shown in <FIG>, <FIG> and <FIG>, the circulation system <NUM>, <NUM> is arranged to circulate at least part of the air heated by the heating element <NUM> around the duct <NUM>, into and through the inner cooking chamber <NUM>, and back into the duct <NUM>.

The at least part of the air heated by the heating element <NUM> may be directed upwardly through the inner cooking chamber <NUM>, as shown in <FIG>, <FIG> and <FIG>. Alternatively, the at least part of the air heated by the heating element <NUM> may be directed downwardly through the inner cooking chamber <NUM>, as shown in <FIG>.

It is also reiterated that in alternative embodiments in which the partition wall <NUM>, the inner cooking chamber <NUM> and the duct <NUM> are omitted, the circulation system <NUM>, <NUM> may provide mass heated air circulation within the cooking chamber <NUM>, with both upward and downward airflow directions through the cooking chamber <NUM> being possible.

With specific reference to <FIG> and <FIG>, the cooking appliance <NUM>, e.g. air fryer, may include an air guide member <NUM> arranged to guide the at least part of the heated air circulated by the circulation system <NUM>, <NUM> into the inner cooking chamber <NUM>.

In such embodiments, the air guide member <NUM> may be arranged in the duct <NUM>. Thus, the air guide member <NUM> may assist to guide the at least part of the heated air from the duct <NUM> into the inner cooking chamber <NUM>.

Any suitable design may be contemplated for the air guide member <NUM>. The air guide member <NUM> may, for example, comprise a so-called star-fish shape. The star-fish shape comprises a plurality of radial fins which are shaped to guide the at least part of the heated air circulated by the circulation system <NUM>, <NUM> into the inner cooking chamber <NUM>.

More generally, the circulation system <NUM>, <NUM> provides an airflow <NUM> within the cooking chamber <NUM> in a direction of the viewing window <NUM>.

Due to the requirement for the image sensor <NUM> to capture images of the food, the viewing window <NUM>, in other words camera viewport, is located in an area near the cooking space in which the food is receivable in the cooking chamber <NUM>. However, this area may be positioned, e.g. fully positioned, in a main cooking airflow path. This may mean that the viewing window <NUM> risks becoming polluted by particles, e.g. oil particles, carried by this airflow.

Air speeds and directions within the cooking chamber <NUM> may be established from computational fluid dynamics (CFD) and laboratory analysis.

For example, cooking appliances <NUM> of the type shown in <FIG> in which the motor <NUM> rotates the fan <NUM> at a speed of <NUM> revolutions per minute +/- <NUM>% have been found to provide the following flow speeds: magnitude: <NUM> - <NUM>/s; X-direction (at/proximal to the top portion 103B): <NUM> - <NUM>/s; Y-direction (at/proximal to the top portion 103B): <NUM> - <NUM>/s; and Z-direction (at/proximal to the top portion 103B): <<NUM>/s.

Values for the flow speeds may vary according to the area of interest, but the above values are considered to provide a representative insight concerning air speeds that can be provided in the area in which the viewing window <NUM> is located.

In general, air speeds provided by the circulation system <NUM>, <NUM> may be in the range of <NUM>-<NUM>/s.

Flow vectors may also be established from CFD analysis. A "snapshot" of a dynamic process in one plane may be derived from such analysis. This may be sufficient to obtain an indication concerning the flow in the area in which the viewing window <NUM> is located.

For example, focusing on the plane in which the viewing window <NUM> is arranged, further insights can be obtained concerning how the air is moving. It can be observed, via splitting into X/Y/Z flow actions, that the Z-direction flow is minor compared to X-direction and Y-direction flows. Thus, airflow in the area in which the viewing window <NUM> is located can be approximated as a planar problem.

Moreover, potential causes of pollution of the viewing window <NUM> may include: (i) "pure" airflow which sporadically transports relatively small particles close to the surface of the viewing window <NUM> which then adhere to this surface; (ii) the airflow coming along with an aerosol, in other words air combined with relatively sticky, e.g. oil-based, particles of various sizes, with higher temperatures of the surface of the viewing window <NUM> increasing the risk of such particles, e.g. oil drops, becoming stuck thereto; and (iii) fat/oil (and potentially water) mixture(s) in the cooking chamber <NUM> becoming sufficiently hot to "explode", with particles being thereby driven towards the surface of the viewing window <NUM>.

Cause (i) may be considered to have a relatively minor influence on pollution of the viewing window <NUM>. However, cause (ii) may have a major influence, noting that the temperature of the surface of the viewing window <NUM> may not be high enough to cause pyrolytic removal of particles, e.g. oil drops, that have become stuck thereto.

The relative influence of cause (iii) may be highly dependent on temperatures, view-related factors and distances. For example, cause (iii) may have less influence if the heating element <NUM> is arranged behind a heat reflector so that the food received in the cooking chamber <NUM> is located in the shadow of the radiation provided by the heating element <NUM>. However, particles arising from the above-mentioned "explosions" may likely form part of the aerosol described in relation to cause (ii).

Referring to <FIG>, <FIG>, <FIG>, <FIG>, the cooking appliance <NUM> according to the present disclosure accordingly includes a flow guiding element <NUM> arranged in a path of the airflow <NUM> provided by the circulation system <NUM>, <NUM> in a direction of the viewing window <NUM>.

As best shown in <FIG>, the flow guiding element <NUM> comprises a ramp <NUM> arranged to displace at least part of the airflow <NUM> away from a plane of the viewing window <NUM>, as denoted by the arrows 123A, and guide the at least part of the airflow <NUM> across the viewing window <NUM>, as denoted by the arrow 123B.

By the ramp <NUM> of the flow guiding element <NUM> redirecting the airflow <NUM> away from the plane of the viewing window <NUM>, pollution of the viewing window <NUM> by, in particular, aerosols generated during cooking of the food received in the cooking chamber <NUM> can be alleviated. Moreover, since the airflow displaced from the plane of the viewing window <NUM> is nonetheless guided by the ramp <NUM> across the viewing window <NUM>, the flow guiding element <NUM> may provide minimal disruption to heated air circulation in the cooking chamber <NUM>, and therefore may exert minimal influence over cooking of the food received in the cooking chamber <NUM>.

The flow guiding element <NUM> can be regarded as flow breaker(s) that redirect flow around the critical area in which the viewing window <NUM> is located, without losing/disrupting the main air frying flow. The latter may ensure that superior cooking performance is maintained in spite of the inclusion of the flow guiding element <NUM>.

It is noted that the flow guiding element <NUM> may be geometrically identifiable, e.g. visible, and its effect may be measurable, e.g. by measuring air speed drop in the relevant area in which the viewing window <NUM> is located.

The flow guiding element <NUM> can be arranged in any suitable manner provided that the flow guiding element <NUM> is able to redirect flow in the above-described manner.

In some embodiments, such as shown in <FIG>, the flow guiding element <NUM> is arranged at or proximal to the top portion 103B of the cooking chamber wall <NUM>. For example, the flow guiding element <NUM> and the viewing window <NUM> may both be arranged at or proximal to the top portion 103B. Thus, the flow guiding element <NUM> may be arranged to minimize pollution of the viewing window <NUM> arranged in or proximal to the top portion 103B.

In some embodiments, such as shown in <FIG>, the ramp <NUM> slopes from the top portion 103B downwardly towards the base portion 103A. The airflow <NUM> may therefore be guided downwardly by the ramp <NUM> towards the base portion 103A of the cooking chamber <NUM>, and thus away from the viewing window <NUM>, e.g. away from the viewing window <NUM> arranged in the top portion 103B.

As a general remark, the airflow <NUM> may be provided along an interior surface <NUM> delimiting, or arranged within, the cooking chamber <NUM>. In other words, the airflow <NUM> may be a surface airflow <NUM> provided along such an interior surface <NUM>.

In some embodiments, the interior surface <NUM> is included in a surface of the cooking chamber wall <NUM> that delimits the cooking chamber <NUM>. Alternatively, the interior surface <NUM> may be included in a surface, e.g. the inner surface, of the partition wall <NUM>.

In embodiments, such as shown in <FIG> and <FIG>, in which the cooking appliance <NUM> comprises the air guide member <NUM>, the air guide member <NUM> may be arranged to guide the airflow <NUM> along the interior surface <NUM>, e.g. the inner surface of the partition wall <NUM>.

In such embodiments, and as best shown in <FIG>, the air guide member <NUM>, e.g. star fish-type air guide member <NUM>, may be arranged to provide a rotational component to the airflow <NUM>, such that the path of the airflow <NUM> winds around the interior surface <NUM>. This rotational component may be provided in addition to the airflow's <NUM> traversing of the height of the inner cooking chamber <NUM>.

In some embodiments, such as shown in <FIG>, <FIG>, <FIG>, <FIG>, the flow guiding element <NUM> comprises a protrusion that protrudes from the interior surface <NUM> along which the airflow <NUM> is provided.

Such a protrusion may provide a relatively straightforward and effective way of implementing the flow guiding element <NUM>, for example relative to alternative solutions involving a ramp-comprising recess defined in the interior surface <NUM>.

In some embodiments, and referring again to <FIG>, the ramp <NUM> extends in the direction of the viewing window <NUM> to a point that is spaced apart from the viewing window <NUM> along an axis A1 extending normal to the viewing window <NUM>. Thus, the ramp <NUM> may extend to a height H that is different from that of the plane of the viewing window <NUM>, thereby facilitating displacement of the airflow <NUM> away from the plane of the viewing window <NUM> and across the viewing window <NUM>.

The flow guiding element <NUM> may comprise a defined edge <NUM> at which extension of the ramp <NUM>, e.g. from the interior surface <NUM>, in the direction of the viewing window <NUM> terminates. Such a defined, e.g. sharp, edge <NUM> may assist to ensure that the airflow 123A initially guided up the ramp <NUM> is directed by the flow guiding element <NUM> across, rather than back towards, the viewing window <NUM>.

In some embodiments, and referring now to <FIG>, the flow guiding element <NUM> is arranged to guide a portion 126A, 126B of the airflow <NUM>, e.g. passing along the interior surface <NUM>, laterally around the viewing window <NUM>. Such lateral guiding of the airflow <NUM> around the viewing window <NUM> may assist to minimize disruption caused by the flow guiding element <NUM> to heated air circulation in the cooking chamber <NUM>, and may thus assist to minimize the flow guiding element's <NUM> influence over cooking of the food received in the cooking chamber <NUM>.

It is noted that the part of the airflow <NUM> denoted by the arrow 126C in <FIG> corresponds to the above-described part of the airflow <NUM> that is displaced by the ramp <NUM> away from the plane of the viewing window <NUM> and guided across the viewing window <NUM>.

In some embodiments, and still referring to <FIG>, the flow guiding element <NUM> comprises sides S1, S2 that face in directions transverse to the airflow <NUM>, with one or both of the sides S1, S2 being connected to a base of the ramp <NUM> via a curved portion CP1, CP2 that curvedly extends from the ramp <NUM> around to the respective side S1, S2. Such curved portion(s) CP1, CP2 may assist the flow guiding element <NUM> to guide the portion 126A, 126B of the airflow laterally around the viewing window <NUM>, as denoted in <FIG> by the arrows 127A, 127B.

<FIG> shows CFD simulated airflows proximal to a viewing window <NUM>, whose location is indicated by the arrow <NUM>, when a spherical flow guiding element <NUM> is arranged adjacent to the viewing window <NUM>.

This CFD simulation was constructed using an idealized space, with an inlet flow of <NUM>/s being applied that enters the air space from the left in the +X direction (from left to right). The spherical flow guiding element <NUM>, which has a diameter of <NUM> in this non-limiting example, was found to lower the airflow speed near the viewing window <NUM> to <NUM> - <NUM>/s compared to <NUM> - <NUM>/s when no flow guiding element <NUM> is employed. This represents an improvement of around a factor of two, which may translate into two times less particulate matter being deposited on the surface of viewing window <NUM> over time.

<FIG> show CFD simulated airflows proximal to a viewing window <NUM> when the flow guiding element <NUM> shown in <FIG> is arranged adjacent to the viewing window <NUM>. This flow guiding element <NUM> design was found to be effective in casting a flow shadow in which the viewing window <NUM> could be located. In this non-limiting example, the airflow speed near the viewing window <NUM> was less than <NUM>/s, corresponding to a factor of five improvement relative to the scenario in which no flow guiding element <NUM> is employed.

<FIG>, in common with <FIG>, illustrates displacement of at least part of the airflow <NUM> away from a plane of the viewing window <NUM> and guiding of the at least part of the airflow <NUM> across the viewing window <NUM>.

<FIG> and <FIG> illustrate guiding of a portion 126A, 126B of the airflow <NUM>, e.g. passing along the interior surface <NUM>, laterally around the viewing window <NUM>, as described above with reference to <FIG>.

This evidence shows that the viewing window <NUM> can be protected from the airflow <NUM>, or at least local flow proximal to the viewing window <NUM> can be markedly reduced, by flow redirection via the flow guiding element <NUM>. In this way, accumulation of pollution on the viewing window <NUM> over time can be minimized or prevented.

It is noted that the flow guiding elements <NUM> shown in <FIG> and <FIG> are provided merely as illustrative non-limiting examples, and the specific shape/form, curvatures, and dimensions of the flow guiding element <NUM> may vary, e.g. according to the particular architecture of the cooking appliance <NUM> in which the flow guiding element <NUM> is to be incorporated.

In some embodiments, such as shown in <FIG>, the flow guiding element <NUM> comprises, e.g. is in the form of, a protrusion that extends at least partly around the viewing window <NUM>, for example with the ramp <NUM> also extending at least partly around the viewing window <NUM>.

In such embodiments, the protrusion may displace air flowing from various directions towards the viewing window <NUM> away from the plane of the viewing window <NUM>, and across the viewing window <NUM>.

The protrusion may, for example, delimit a hole, e.g. a frustroconical hole, through which light passes to reach the viewing window <NUM>.

Alternatively or additionally, the protrusion may be detachable from the interior surface <NUM>.

This may assist with cleaning the viewing window <NUM> (as well as the protrusion itself), particularly in embodiments in which the protrusion extends at least partly around the viewing window <NUM>.

In some embodiments, such as shown in <FIG> and <FIG>, the viewing window <NUM> is arranged in the top portion 103B, and in particular in the heat reflector.

This positioning of the viewing window <NUM>, as well as facilitating image capture of food within the cooking chamber <NUM>, may assist to protect the image sensor <NUM> from the heat within the cooking chamber <NUM>.

Alternatively or additionally, the flow guiding element <NUM> may be arranged at or proximal to the top portion 103B, and in particular at or proximal to the heat reflector.

In some embodiments, such as shown in <FIG>, the flow guiding element <NUM> may be arranged at a corner of the top portion 103B, e.g. heat reflector.

This corner-positioning of the flow guiding element <NUM> may facilitate design of the flow guiding element <NUM>, e.g. with appropriate dimensions, curvatures, etc., to provide enhanced redirection of the airflow <NUM> away from the viewing window <NUM>.

Moreover, such corner positioning of the flow guiding element <NUM> may reflect that in practice, e.g. in a real cooking appliance <NUM> architecture, the viewing window <NUM> and the image sensor <NUM> may be ideally positioned at or proximal to the top portion 103B, e.g. heat reflector, to facilitate imaging of the cooking space by the image sensor <NUM>.

Claim 1:
A cooking appliance (<NUM>) comprising:
a cooking chamber (<NUM>);
a heating element (<NUM>);
a viewing window (<NUM>);
an image sensor (<NUM>) arranged to enable image capture of food received in the cooking chamber through the viewing window;
and a circulation system (<NUM>, <NUM>) , the cooking appliance being characterized in that said circulation system (<NUM>, <NUM>) is arranged to circulate air heated by the heating element in the cooking chamber; and in that
a flow guiding element (<NUM>) is arranged in a path of an airflow (<NUM>) provided by the circulation system in a direction of the viewing window, the flow guiding element comprising a ramp (<NUM>) arranged to displace at least part of the airflow away from the viewing window and guide said at least part of the airflow across the viewing window.