DETECTING A STANDSTILL OF A ROTATABLE MICROWAVE DISTRIBUTION DEVICE

Abstract

In a method for detecting a standstill of a rotatable microwave distribution apparatus of a household microwave appliance, while microwaves are being supplied into a cooking compartment of the household microwave appliance, a microwave leakage radiation for angle-dependent recurring fluctuations is monitored and an action in the absence of such fluctuations being detected.

Claims

1-10. (canceled)

11. A method for detecting a standstill of a rotatable microwave distribution apparatus of a household microwave appliance, said method comprising: while microwaves are being supplied into a cooking compartment of the household microwave appliance, monitoring a microwave leakage radiation for angle-dependent recurring fluctuations; and triggering an action in the absence of such fluctuations being detected.

12. The method of claim 11, further comprising rotating the microwave distribution apparatus uniformly in a circumferential manner, wherein the microwave leakage radiation is monitored for periodically recurring fluctuations.

13. The method of claim 11, wherein the microwave leakage radiation is monitored by monitoring a periodically recurring sequence of a pattern in a curve of the microwave leakage radiation.

14. The method of claim 13, wherein the microwave leakage radiation is monitored for a periodically recurring sequence of at least one minimum and at least one maximum that have a predetermined minimum value gap with respect to one another.

15. The method of claim 13, further comprising continuously comparing a cross correlation of a stored section of the curve of the microwave leakage radiation to a section of the curve that is currently received.

16. The method of claim 11, wherein the microwave leakage radiation comprises multiple microwave leakage radiations that are measured at different leakage sites, with each said microwave leakage radiation being monitored for angle-dependent recurring fluctuations.

17. The method of claim 11, wherein the microwave leakage radiation comprises microwave leakage radiations that occur in an overlapping manner at multiple different leakage sites, with the microwave leakage radiation being monitored for angle-dependent recurring fluctuations.

18. The method of claim 13, further comprising providing the rotatable microwave distribution apparatus with at least one of a rotary antenna and a wobbler.

19. A household microwave appliance, comprising: a cooking compartment; a microwave generator generating microwaves for supply into the cooking compartment; a rotatable microwave distribution apparatus configured to vary a field distribution of microwaves that are supplied into the cooking compartment; a leakage radiation measuring apparatus configured to measure a microwave leakage radiation; and a data processing apparatus connected to the leakage radiation measuring apparatus, said data processing apparatus configured to monitor a microwave leakage radiation for angle-dependent recurring fluctuations while microwaves are being supplied into the cooking compartment and to trigger an action in the absence of such fluctuations being detected.

20. The household microwave appliance of claim 19, wherein the household microwave appliance is a baking oven having a microwave functionality.

Description

[0038] The above-described properties, features and advantages of this invention and also the manner in which these are achieved, become clearer and more explicitly understandable in conjunction with the following schematic description of an exemplary embodiment that is further explained in conjunction with the drawings.

[0039] FIG. 1 shows a household microwave appliance as a sectional view in a side view;

[0040] FIG. 2 shows a curve of an intensity of a microwave leakage radiation when the rotary antenna is rotating as well as when the rotary antenna is at a standstill; and

[0041] FIG. 3 shows a section from a measuring curve that is illustrated in FIG. 2 in the region of a time period with a rotating rotary antenna.

[0042] FIG. 1 illustrates as a sectional view in a side view a sketch of a household microwave appliance 1 having a cooking compartment 2. The cooking compartment 2 is surrounded by a cooking compartment wall 3 that has a front-side loading hatch that can be closed with a door 4. The household microwave appliance 1 has at least one microwave generator 5 for the treatment of food (not illustrated) that is located in the cooking compartment 2, where applicable also further heating elements such as one or multiple resistance heating elements (not illustrated). The household microwave appliance 1 can then be in particular a baking oven having a microwave functionality.

[0043] The microwave generator 5 is connected to a microwave guide 6 that issues on the other side into a dome 7 that is arranged on the lid side. Microwaves MW that are generated by the microwave generator 5 are guided by means of the microwave guide 6 into the dome 7 from where said microwaves pass into the cooking compartment 2. A microwave distribution apparatus in the form of a rotatable rotary antenna 8 is located for this purpose in the dome 7 and the microwaves MW that arrive from the microwave guide 6 are radiated by means of said rotatable rotary antenna. The rotary antenna 8 can rotate by means of a motor, in particular a stepper motor 9, as an antenna motor, for example almost continuously in steps of 1°.

[0044] The step motor 9 can be controlled by means of a control facility 10 that is moreover connected to a leakage radiation measuring apparatus in the form of a microwave sensor 11 and is configured so as to evaluate measuring data Sig that is generated by the microwave sensor 11. The microwave sensor 11 is arranged outside or behind the cooking compartment wall 3 and namely behind or in the vicinity of an opening 12 of the cooking compartment wall 3 and said opening allows microwave leakage radiation LS to pass through. The intensity of the microwave leakage radiation LS typically changes during the course of a rotation of the rotary antenna 8 together with the field distribution of the microwaves MW in the cooking compartment 2.

[0045] Moreover, an operating facility 13 is provided that is coupled to the control facility 10 and said operating facility can have one or multiple operating elements and one or multiple display facilities, for example in the form of a touch-sensitive screen. The control facility 10 is configured so as to output one or multiple instructions or messages to a user on a display facility of the operating facility 13.

[0046] The control facility 10 is also configured so as to detect that the activated rotary antenna 8 is at a standstill and thereupon to trigger at least one action. The control facility 10 is consequently also used for this purpose as a data processing apparatus or evaluating circuit. In particular, the control facility 10 is configured so as to monitor the microwave leakage radiation LS that is measured by means of the microwave sensor 11 for angle-dependent recurring fluctuations in the rotational operation of the rotary antenna 8 while microwaves are being supplied into the cooking compartment 2 and if said control facility detects an absence of such fluctuations, said control facility is configured so as to trigger at least one action, for example to output a corresponding message to the operating facility 13 and/or to transmit said corresponding message to a mobile user end device, etc.

[0047] FIG. 2 illustrates a curve of an intensity of a microwave leakage radiation LS that is measured by means of the microwave sensor 11 when the rotary antenna 8 is rotating as well as when the rotary antenna is at a standstill wherein measurement values Sig of the microwave sensor 11 in mV are plotted against a time tin s.

[0048] The measuring curve illustrates after the start of a microwave operation alternating time periods M in which the rotary antenna 8 rotates uniformly and time periods S in which the rotary antenna 8 does not rotate. Whereas the measurement signal Sig only changes slightly in the time periods S, intense fluctuations of the measurement signal Sig occur in the time periods M. The absence of such fluctuations consequently indicates that the rotary antenna 8 is at a standstill.

[0049] FIG. 3 illustrates a section of the measurement curve that is illustrated in FIG. 2 in the range of a time period M. The time period M comprises three consecutive full rotations RP1, RP2 and RP3. Because the rotary antenna 8 rotates uniformly during the time period M, a point in time on the x-axis for a measurement value corresponds to a respective rotational angle of the rotary antenna 8. In the illustrated exemplary embodiment, alternately a first maximum Max1, a minimum Min and a second maximum Max2 occur during a full rotation of the rotary antenna 8 in the signal curve or in the curve.

[0050] For example, it is possible by means of the control facility 10 to initially automatically identify the extreme values Max1, Min, Max2 from the curve progression during the first full rotations RP1. Then it is possible by means of the control facility 10 to monitor for whether during an activated rotation of the rotary antenna 8 these extreme values Max1, Min, Max2 occur again or periodically occur or do not occur in the following rotations RP2 and RP3. In particular, it is possible to additionally monitor for whether a minimum value gap (Min/Max-delta) between Max1 and Min and/or a minimum value gap between Min and Max2 is above an in particular respective threshold value or not. This threshold value can be for example 20% of an average value of the relevant minimum Min and maximum Max1, Max2.

[0051] It is therefore possible by means of the control facility 10 for the rotation RP1 to be monitored for whether the following applies.

Sig(Max1)−Sig(Min)□≥0.2.Math.[Sig(Max1)+Sig(Min)]/2

and/or

Sig(Max2)−Sig(Min)□≥0.2.Math.[Sig(Max2)+Sig(Min)]/2

[0052] This is provided during the time period M since as an estimate the following applies,

80−35=45≤0.2.Math.57.5=11.5

or

120−35=85≤0.2.Math.77.5=15.5

[0053] while these boundary conditions are not met in the time periods S. In a similar manner, it is also possible to monitor a value gap between Max1 and Max2.

[0054] If it is identified by means of the control facility 10 that during the following rotations RP2, RP3 the extreme values Max1, Min, Max2 do not occur again or one of both of the above gap conditions is not met, said control facility triggers at least one action.

[0055] Obviously, the present invention is not limited to the illustrated exemplary embodiment.

[0056] In general, it is possible for “a”, “an” or one to be understood as singular or a plurality, in particular in the sense of “at least one” or “one or multiple” etc. so long as this is not explicitly ruled out, for example by the expression “precisely one” etc.

[0057] It is also possible for the disclosure of a number to include precisely the disclosed number as well as a customary tolerance range so long as this is not explicitly ruled out.

LIST OF REFERENCE NUMERALS

[0058] 1 Household microwave appliance [0059] 2 Cooking compartment [0060] 3 Cooking compartment wall [0061] 4 Door [0062] 5 Microwave generator [0063] 6 Microwave guide [0064] 7 Dome [0065] 8 Rotary antenna [0066] 9 Stepper motor [0067] 10 Control facility [0068] 11 Microwave sensor [0069] 12 Opening [0070] 13 Operating facility [0071] LS Microwave leakage radiation [0072] M Time period in which the rotary antenna is rotating [0073] Max1 First maximum [0074] Max2 Second maximum [0075] Min Minimum [0076] MW Microwaves [0077] RP1 First full rotation [0078] RP2 Second full rotation [0079] RP3 Third full rotation [0080] S Time period in which the rotary antenna is not rotating [0081] Sig Measurement signal [0082] t Time