MICROWAVE APPLIANCE AND METHOD FOR OPERATING A MICROWAVE

Abstract

A microwave appliance includes a microwave facility which generates microwaves and introduces the microwaves into a cooking compartment and which is operable with at least two configurations to generate different field distributions of the microwaves in the cooking compartment. A temperature acquisition facility contactlessly acquires a heat distribution in the cooking compartment, and a data processing facility identifies a non-food to be cooked region in the cooking compartment from the acquired heat distribution. A control facility sets a current configuration of the microwave facility and operates the microwave facility The control facility selects or sets at least one of the configurations of the microwave facility with regard to reducing a power of the microwaves in the identified non-food to be cooked region.

Claims

1-12. (canceled)

13. A microwave appliance, comprising: a microwave facility configured to generate microwaves and introduce the microwaves into a cooking compartment, said microwave facility operable with at least two configurations to generate different field distributions of the microwaves in the cooking compartment; a temperature acquisition facility configured to contactlessly acquire a heat distribution in the cooking compartment, a data processing facility configured to identify a non-food to be cooked region in the cooking compartment from the acquired heat distribution; and a control facility configured to set a current configuration of the microwave facility and to operate the microwave facility, said control facility configured to select or set at least one of the configurations of the microwave facility with regard to reducing a power of the microwaves in the identified non-food to be cooked region.

14. The microwave appliance of claim 13, wherein the data processing facility is configured to identify the non-food to be cooked region based on a temperature level thereof.

15. The microwave appliance of claim 13, wherein the data processing facility is configured to identify the non-food to be cooked region based on a temperature difference between components of the non-food to be cooked region and a food to be cooked.

16. The microwave appliance of claim 13, wherein the data processing facility is configured to identify the non-food to be cooked region based on a different speed of a temperature change between components of the non-food to be cooked region and a food to be cooked.

17. The microwave appliance of claim 13, wherein the data processing facility is configured to identify a type of a component of the non-food to be cooked region situated in the cooking compartment based on a heating curve thereof.

18. The microwave appliance of claim 13, wherein the data processing facility is configured to identify a component of the non-food to be cooked region by a presence of a marker arranged on the component.

19. The microwave appliance of claim 13, wherein the data processing facility is configured to determine the non-food to be cooked region during a heating-up phase.

20. The microwave appliance of claim 13, further comprising a thermal radiation heating element, said control facility configured to activate the thermal radiation heating element during a heating-up phase.

21. The microwave appliance of claim 13, further comprising a thermal radiation heating element, said control facility configured to activate the thermal radiation heating element during a preheating phase.

22. The microwave appliance of claim 13, wherein each of the configurations comprises a setting parameter with a plurality of setting values.

23. The microwave appliance of claim 22, wherein the setting parameter is selected from the group consisting of phase of the microwaves, frequency of the microwaves, power of the microwaves, orientation of a movable antenna and/or a wobbler, and rotational speed of a movable antenna and/or a wobbler.

24. A method for operating a microwave appliance, said method comprising the steps of: a) heating up a cooking compartment of the microwave appliance; b) acquiring a heat distribution in the cooking compartment in a contactless manner; c) determining a non-food to be cooked region in the cooking compartment from the heat distribution; and d) setting a field distribution of microwaves in the cooking compartment such that a region with high field strength in the non-food to be cooked region is avoided.

25. The method of claim 24, further comprising: iterating the steps a) to d); varying the field distribution of microwaves in the cooking compartment to provide plural field distributions; and subsequently selecting a field distribution of the plural field distributions sufficient to avoid the region with high field strength in the non-food to be cooked region.

Description

[0063] The above-described properties, features and advantages of this invention and the manner in which these are achieved will become clearer and more readily understandable in connection with the following schematic description of an exemplary embodiment, which will be described in further detail making reference to the drawings.

[0064] FIG. 1 shows a sectional representation in a side view of a household cooking appliance in the form of an oven with a microwave facility and

[0065] FIG. 2 shows procedure steps of a possible method for setting a configuration of the microwave facility.

[0066] FIG. 1 shows a household cooking appliance in the form of an oven 1 with integrated microwave functionality. The oven 1 has a cooking compartment 2, which is delimited by a cooking compartment wall 3, the front loading opening of which being able to be closed by means of a cooking compartment door 4 which is impermeable to microwaves and thermally insulated.

[0067] To heat food to be cooked G situated in the cooking compartment 2, it can be heated by means of at least one thermal radiation heating element (e.g. a bottom heating element, top heating element, grill heating element and/or hot air heating element, indicated here by a bottom heating element 5).

[0068] The oven 1 furthermore has a microwave facility 6 with a rotary antenna 7 which is able to rotate. By way of the rotary antenna 7, it is possible for microwaves generated by the microwave facility 6 to be introduced into the cooking compartment 2, wherein they assume a particular microwave field distribution or field pattern. The operation of the thermal radiation heating element 5 and the microwave facility 6, including a rotational position or a rotational angle of the rotary antenna 7 which is able to rotate in a horizontal plane, can be set in a targeted manner via a control facility 8. For example, the rotational position of the rotary antenna 7 can be set in steps of 1°, 5°, 10° or the like.

[0069] The oven 1 additionally has a temperature acquisition facility for the contactless acquisition of a heat distribution in the cooking compartment 2 in the form of a thermal imaging camera 9 which measures in pixels. The food to be cooked G, which is accommodated in a container for food to be cooked S, which in turn rests on an accessory in the form of an oven shelf R or the like, is situated in a field of view F of the thermal imaging camera 9, as is the accessory.

[0070] The control facility 8 is used to control the oven 1 and is also used to evaluate the heat distributions or thermal images ascertained by the thermal imaging camera 9. The thermal images are constructed in a pixel-like manner and have a resolution of 16×16, 32×24, 64×64, 128×64, 256×256, 512×512 or 2048×2048 pixels, for example, but are not restricted thereto. The control facility 8 is further used as a data processing facility for evaluating the thermal images, in particular for identifying a non-food to be cooked region in the cooking compartment 2 in at least one thermal image.

[0071] FIG. 2 shows procedure steps of a possible method for operating the oven 1, in particular for setting a configuration of the microwave facility 6, 7.

[0072] In step S1, a preheating phase of the oven is activated, wherein the cooking compartment 2 is only heated by the at least one thermal radiation heating element 5. The microwave facility 6, 7 remains deactivated during the preheating phase.

[0073] In step S2, the thermal imaging camera 9 is used to record a plurality of thermal images at sufficient temporal intervals.

[0074] In step S3, the thermal images are evaluated by the control facility 8 in that different absolute temperatures and/or heating rates of different regions in the thermal images are identified and regions with particularly high temperatures and/or heating rates are assigned to an accessory, e.g. the oven shelf R. The oven shelf R can be identified by a grid pattern that appears bright in the thermal images, for example. This can be confirmed by a typical heating progression for the oven shelf R.

[0075] In step S4, when the preheating phase is terminated—possibly with the deactivation of the at least one thermal radiation heating element 5—the cooking compartment door 4 is opened, the food to be cooked G is introduced into the cooking compartment 2 and the cooking compartment door 4 is then closed again. This opening and closing of the cooking compartment door 4 is identified automatically.

[0076] Subsequently, the control facility 8 actuates the thermal imaging camera 9 in order to record a thermal image of the cooking compartment 2 and to compare this thermal image with at least one thermal image recorded in step S3. By evaluating differences in the thermal images, the food to be cooked G (in the form of a colder region left out of the regular grid pattern from the perspective of the thermal imaging camera 9) and the non-food to be cooked region 3, 4, R are identified.

[0077] Subsequently, in step S5, the microwave facility 6, 7 is operated in a particular configuration. In this context, a setting parameter of the configuration can correspond to a rotational position of the rotary antenna 7.

[0078] In one variant, the microwave facility 6, 7 is only activated with a configuration which knows that it does not generate hot spots in the non-food to be cooked region. In another variant, the microwave facility 6, 7 is activated successively with different configurations, which e.g. correspond to different rotational positions of the rotary antenna 7, which know that they all do not generate hot spots in the non-food to be cooked region. This enables a particularly uniform heating of the food to be cooked G. This can be continued until the end of the cooking phase or the treatment procedure.

[0079] In another variant, in step S5, a randomly chosen configuration of the microwave facility 6, 7 is set and it is operated with said configuration.

[0080] Subsequently, in step S6 a thermal image of the cooking compartment 2 is recorded and in step S7 it is examined whether a noticeable local temperature increase occurs in the previously identified or determined non-food to be cooked region, which may in particular indicate a hot spot, e.g. in the region of the oven shelf R and/or in the region of a cooking compartment wall 3.

[0081] If this is the case (“Y”), then in step S8 the currently set configuration is saved as “not suitable” and the method branches back to step S5, where another configuration for the microwave facility 6, 7 is randomly set.

[0082] If this is not the case (“N”), then the current configuration can be retained in one variant for the rest of the cooking procedure or treatment procedure. Alternatively, the currently set configuration can be saved as “suitable” and it can then be examined in step S9 whether a predefined number (e.g. two, three, four or more) of suitable configurations have already been found.

[0083] If this is not the case (“N”), then it is possible to branch back to step S5 and set a further randomly chosen configuration at the microwave facility 6, 7.

[0084] If this is the case (“Y”), then the microwave facility 6, 7 can then in step S10 only be operated with the suitable configurations in an alternating manner.

[0085] The method described above is performed until, in step S11, a stopping criterion has been reached, e.g. a period of time specified on the user side or program side has expired.

[0086] The present invention is of course not restricted to the exemplary embodiment shown.

[0087] In general, “a”, “an”, etc. can be understood as singular or plural, in particular in the sense of “at least one” or “one or more”, etc., provided this is not explicitly excluded, e.g. by the expression “precisely one”, etc.

[0088] A numerical value can also include the given value as well as a typical tolerance range, provided this is not explicitly excluded.

LIST OF REFERENCE CHARACTERS

[0089] 1 Oven [0090] 2 Cooking compartment [0091] 3 Cooking compartment wall [0092] 4 Cooking compartment door [0093] 5 Thermal radiation heating element [0094] 6 Microwave facility [0095] 7 Rotary antenna [0096] 8 Control facility [0097] 9 Thermal imaging camera [0098] F Field of view [0099] G Food to be cooked [0100] R Oven shelf [0101] S Container for food to be cooked [0102] S1-S11 Method steps