COOKING APPLIANCE HAVING A PLANAR ANTENNA AND METHOD FOR OPERATING A COOKING APPLIANCE

Abstract

A cooking appliance includes a cooking chamber for cooking a product to be cooked. An air-guiding plate is arranged in the cooking chamber and coupled by a coupling device to a transmitter/receiver unit which transmits and/or receives a high frequency signal. The air-guiding plate is configured as a planar antenna for transmitting the high frequency signal between the coupling device and a sensor that can be arranged in the cooking chamber.

Claims

1-15. (canceled)

16. A cooking appliance, comprising: a cooking chamber for cooking a product to be cooked; an air-guiding plate arranged in the cooking chamber; a transmitter/receiver unit configured to transmit and/or receive a high-frequency signal; a coupling device configured to couple the transmitter/receiver unit and the air-guiding plate; and a sensor configured for arrangement in the cooking chamber, said air-guiding plate being configured in the form of a planar antenna for transmitting the high-frequency signal between the coupling device and the sensor.

17. The cooking appliance of claim 16, wherein the coupling device comprises a spiral-shaped electrical line for capacitive coupling with the air-guiding plate for transmitting the high-frequency signal.

18. The cooking appliance of claim 17, wherein the spiral-shaped electrical line is arranged to a rear, to a front, above, below or to a side relative to the air-guiding plate.

19. The cooking appliance of claim 17, further comprising a mounting configured to fix the air-guiding plate to at least one side wall of the cooking chamber, said spiral-shaped electrical line being arranged relative to the air-guiding plate at a position which is dependent on the position of the mounting.

20. The cooking appliance of claim 17, wherein the spiral-shaped electrical line is arranged relative to the air-guiding plate at a position which is dependent on a spacing of an edge of the air-guiding plate from a side wall of the cooking chamber, such that an impedance of the air-guiding plate is adapted to an impedance of the coupling device.

21. The cooking appliance of claim 17, wherein the spiral-shaped electrical line is configured as a component which is removable or capable of being added.

22. The cooking appliance of claim 20, wherein the air-guiding plate has an opening for passage of the component.

23. The cooking appliance of claim 17, wherein the spiral-shaped electrical line is produced from a heat-resistant spring material.

24. The cooking appliance of claim 16, wherein the air-guiding plate is produced from a steel plate which is coated with an electrically insulating layer.

25. The cooking appliance of claim 16, wherein the air-guiding plate is enameled.

26. The cooking appliance of claim 16, further comprising an earth line configured to galvanically couple an earth for the planar antenna to a side wall of the cooking chamber.

27. The cooking appliance of claim 16, wherein the planar antenna is configured to transmit the high-frequency signal in an ISM band.

28. The cooking appliance of claim 16, wherein the transmitter/receiver unit is configured in at least one of three ways, a first way in which the transmitter/receiver unit transmits a first high-frequency signal via the planar antenna to the sensor, a second way in which the transmitter/receiver unit receives a second high-frequency signal provided by the sensor via the planar antenna at a predeterminable time, a third way in which the transmitter/receiver unit receives the second high-frequency signal provided by the sensor via the planar antenna in response to a presence of a triggering signal.

29. The cooking appliance of claim 16, further comprising at least one member selected from the group consisting of a heating coil, a steam generator, a microwave generator and a fan.

30. The cooking appliance of claim 16, being constructed as at least one member selected from the group consisting of an oven, a microwave oven and a steam cooker.

31. A method for operating a cooking appliance which includes a cooking chamber and a coupling device for coupling a transmitter/receiver unit and an air-guiding plate which is arranged in the cooking chamber, said method comprising transmitting between the transmitter/receiver unit and a sensor arranged in the cooking chamber, a high-frequency signal via a planar antenna which forms the air-guiding plate.

Description

[0047] Further advantageous embodiments and aspects of the invention form the subject-matter of the subclaims and the exemplary embodiments of the invention described hereinafter. Moreover, the invention is described in more detail by means of preferred embodiments with reference to the accompanying figures.

[0048] FIG. 1 shows a schematic block diagram of an embodiment of a cooking appliance;

[0049] FIG. 2 shows a schematic block diagram of an embodiment of a coupling device;

[0050] FIG. 3 shows a schematic block diagram of a further embodiment of a cooking appliance;

[0051] FIG. 4 shows a time diagram as an example of the presence of a triggering signal;

[0052] FIG. 5 shows a schematic block diagram of a further embodiment of a cooking appliance;

[0053] FIG. 6 shows a schematic block diagram of a further embodiment of a cooking appliance;

[0054] FIG. 7 shows a schematic block diagram of a front view of a further embodiment of a cooking appliance; and

[0055] FIG. 8 shows a flow diagram of a method for operating a cooking appliance.

[0056] Elements which are the same or functionally the same are provided with the same reference characters in the figures, provided nothing further is specified.

[0057] FIG. 1 shows a schematic block diagram of an embodiment of a cooking appliance 1. The cooking appliance 1 shown comprises a cooking chamber 2 in which a product 3 to be cooked is located. A sensor 9 is fixed in the product 3 to be cooked. Moreover, the cooking appliance 1 comprises a transmitter/receiver unit 5, a coupling device 7 and an air-guiding plate 4, which is fixed by means of a mounting 17 to a side wall 16 of the cooking chamber 2.

[0058] In the exemplary embodiment of FIG. 1, for example, a high-frequency signal 6 is generated in the transmitter/receiver unit 5. The high-frequency signal 6 is transmitted by means of the coupling device 7 by the transmitter/receiver unit 5 to the air-guiding plate 4. The coupling device 7 is capacitively coupled with the air-guiding plate 4, which in the view of FIG. 1 is shown by a gap between the coupling device 7 and the air-guiding plate 4. The high-frequency signal 6 is shown by means of a double arrow connected by a dashed line. The air-guiding plate 4 is designed in the exemplary embodiment as a planar antenna 8. The planar antenna 8 is designed to emit the high-frequency signal 6 into the cooking chamber 2. The high-frequency signal 6 may, therefore, be transmitted to the sensor 9 fixed in the product 3 to be cooked. For example, the sensor 9 receives the high-frequency signal 6 and in turn generates a further high-frequency signal 6 which is received by the planar antenna 8 and by means of the capacitive coupling may be transmitted to the coupling device 7 and further to the transmitter/receiver unit 5. The transmitter/receiver unit 5 is designed to interpret the further high-frequency signal 6 received. The sensor 9 is, for example, a skewer thermometer, wherein the high-frequency signal 6 is then designed to transmit temperature information. The high-frequency signal 6 is located, in particular, in a frequency range of 433.05-434.79 MHz.

[0059] Deviating from the view of FIG. 1 the transmitter/receiver unit 5 may also be arranged outside the cooking chamber 2 (see for example FIG. 6). Then the coupling device 7 may then be passed through an opening in the side wall 16 provided therefor.

[0060] FIG. 2 shows a schematic block diagram of an embodiment of a coupling device 7 which is configured as a spiral-shaped electrical line 10. In the example of FIG. 2, the coupling device 7 is shown as a coaxial cable 7. The coaxial cable 7 comprises, in particular, a core 10 and a shield 11. Both the core 10 and the shield 11 are produced from electrically conductive materials.

[0061] In the example of FIG. 2 the core 10 of the coaxial cable 7 is configured as the spiral-shaped electrical line 10. To this end, an end of the spiral-shaped electrical line 10 is curved in a spiral shape. This arrangement has the advantage that the high-frequency signal 6 may be capacitively transmitted in a particularly efficient manner, since a large surface of the air-guiding plate 4 is covered, whereby the interaction between the electrical line 10 and the air-guiding plate 4 is increased. The shield 11 is preferably galvanically coupled (not shown) to an earth, particularly preferably to the side wall 16 of the cooking chamber 2. Such a galvanic coupling may be achieved, for example, by means of a direct screw connection of the shield 11 to the side wall 16.

[0062] A suitable dielectric material is preferably located between the core 10 and the shield 11 in order to avoid a short circuit. Moreover, the shield 11 is preferably enclosed by an insulating layer in order to avoid faulty contacts.

[0063] FIG. 3 shows a schematic block diagram of a further embodiment of a cooking appliance 1 comprising a cooking chamber 2, an air-guiding plate 4 and a plurality of spiral-shaped electrical lines 10. The plurality of spiral-shaped electrical lines 10 forms as a whole the coupling device 7 (not shown). The air-guiding plate 4 of FIG. 3 configured as a planar antenna 8 also comprises an opening 18, which is designed for passing a component through, and a plurality of air openings 19. In the example of FIG. 3 the plurality of air openings 19 is arranged in a circle.

[0064] By the use of a plurality of spiral-shaped electrical lines 10 an optimized transmission of the high-frequency signal 6 to the air-guiding plate 4 may be achieved. In this case, the arrangement of the spiral-shaped electrical lines 10 may be selected as desired. In particular, the arrangement of the spiral-shaped electrical lines 10 may be selected such that further structural conditions of the cooking appliance 1 may be fulfilled. In the example of FIG. 3, in each case a spiral-shaped electrical line 10 is located below, above and to the right of the air-guiding plate 4. However, it is also conceivable that a plurality of the spiral-shaped electrical lines 10 may be arranged above, below, to the front, to the rear, and/or to the side adjacent to the air-guiding plate 4. Moreover, it is conceivable that individual spiral-shaped electrical lines 10 differ from one another. Such a difference could, for example, be in the configuration of the spiral shape.

[0065] The opening 18 of the air-guiding plate 4 of FIG. 3 is suitable, in particular, for a spiral-shaped electrical line 10 designed as a separate component to be able to be passed through said opening. Thus a spiral-shaped electrical line 10 mounted to the rear of the air-guiding plate 4 in a receiver (not shown) provided therefor, is accessible from the front through the air-guiding plate 4 and may be removed from the cooking appliance 1 or alternatively added thereto.

[0066] Moreover, the air openings 19 are suitable, in particular, for deflecting an airflow in the cooking chamber 2. Moreover, the air openings 19 may be suitable for influencing the physical properties of the air-guiding plate 4 which is configured as a planar antenna 8, such that the transmission properties of the planar antenna 8 are optimized.

[0067] FIG. 4 shows a time diagram as an example of the presence of a triggering signal. FIG. 4 shows a diagram with a time axis t and a signal axis S. The signal axis S in this case is shown as a binary system with the values 0 and 1. In the view of FIG. 4, for example, a measurement is started at a time t1. The measurement is intended to take place such that after a time period t=t2t1 has passed the sensor 9 is read. After the time period t has passed, at the time t2, therefore the triggering signal is present. This is shown in FIG. 4 as a signal level 1 on the signal axis S. The triggering signal causes the transmitter/receiver device 5 to generate the high-frequency signal 6 in order to read the sensor 9.

[0068] As an alternative to this view, many further sequences of triggering signals are conceivable, for example triggering signals occurring periodically or triggering signals triggered by a further event, for example the actuation by a user of a control element provided therefor. With a periodic sequence of triggering signals a time period t between two successive triggering signals preferably has a duration in the range of seconds, i.e. 0.5 s, 1 s or even 10 s.

[0069] FIG. 5 shows a schematic block diagram of a further embodiment of a cooking appliance 1. In the example of FIG. 5 the cooking appliance 1 comprises, in addition to the devices shown in FIGS. 1, 3, 6 and/or 7, a heating coil 12, a steam generator 13, a microwave generator 14 and a fan 15.

[0070] FIG. 6 shows a schematic block diagram of a further embodiment of a cooking appliance 1. The cooking appliance 1 is shown in a side view. The cooking appliance 1 comprises a cooking chamber 2 with a product 3 to be cooked located therein. A sensor 9 is fixed in the product 3 to be cooked. Moreover, the cooking appliance 1 comprises a transmitter/receiver unit 5, a coupling device 7 with a spiral-shaped electrical line 10, and an air-guiding plate 4 which is configured as a planar antenna 8 which is arranged parallel to the side wall 16. Moreover, the cooking appliance 1 comprises a heating coil 12 and a fan 15. In particular, in the exemplary embodiment of FIG. 6 the transmitter/receiver unit 5 is arranged outside the cooking chamber 2. The coupling device 7 for coupling the air-guiding plate 4 to the transmitter/receiver unit 5 is passed through an opening in the side wall 16 designed therefor.

[0071] FIG. 7 shows a schematic block diagram of a front view of a further embodiment of a cooking appliance 1. In the example, the transmitter/receiver unit 5 is arranged outside the cooking chamber 2. The further functional elements, such as the coupling device 7 with the electrical line 10, are covered by the air-guiding plate 4 and, therefore, not shown in FIG. 7. The air-guiding plate 4, which is configured as a planar antenna 8, in the example has a plurality of air openings 19. Moreover, four mountings 17 are shown, the air-guiding plate 4 being fixed thereby to a side wall 16.

[0072] FIG. 8 shows a flow diagram of a method for operating the cooking appliance 1, in particular according to one of the embodiments of FIGS. 1, 3, or 5-7. The cooking appliance 1 comprises a cooking chamber 2 for cooking a product 3 to be cooked, an air-guiding plate 4 arranged in the cooking chamber 2 and configured as a planar antenna 8, a transmitter/receiver unit 5 for transmitting and/or receiving a high-frequency signal 6 and a coupling device 7 for coupling the transmitter/receiver unit 5 and the air-guiding plate 4, as well as a sensor 9 arranged in the cooking chamber 2.

[0073] In step 801 the high-frequency signal 6 is transmitted between the transmitter/receiver unit 5 and the sensor 9 by means of the planar antenna 8.

[0074] In step 802 the transmitted high-frequency signal 6 is interpreted by the transmitter/receiver unit 5.

[0075] Step 802 in this case is optional since the transmitter/receiver unit 5 may conduct the received high-frequency signal 6 further, for example also to a control device of the cooking appliance 1, which then undertakes the interpretation of the high-frequency signal 6.

[0076] Although the present invention has been described with reference to exemplary embodiments it may be modified in many different ways.

REFERENCE CHARACTERS USED

[0077] 1 Cooking appliance [0078] 2 Cooking chamber [0079] 3 Product to be cooked [0080] 4 Air-guiding plate [0081] 5 Transmitter/receiver unit [0082] 6 High-frequency signal [0083] 7 Coupling device [0084] 8 Planar antenna [0085] 9 Sensor [0086] 10 Electrical line [0087] 11 Shield [0088] 12 Heating coil [0089] 13 Steam generator [0090] 14 Microwave generator [0091] 15 Fan [0092] 16 Side wall [0093] 17 Mounting [0094] 18 Opening [0095] 19 Air openings [0096] 801 Method step [0097] 802 Method step [0098] t Time axis [0099] t1 Time [0100] t2 Time [0101] t Time period [0102] S Signal axis