Mobile kitchen appliance with integrated weighing unit

Abstract

The invention relates to a mobile kitchen appliance with an integrated weighing unit, comprising a housing (10), in the top side of which a cover plate (20) is provided as a weighing surface, and at least three weighing sensors (41, 42) which are arranged between the housing (10) and the feet (40) and are designed to detect sensor data in relation to a force, which acts on the top side (21) of the cover plate (20), an operating device (30) of the kitchen appliance, and control electronics, which are connected to the weighing sensors (41, 42) for detecting the sensor data and to the operating device (30) for controlling the operating device (30) of the kitchen appliance. At least one input zone (53) is provided on the top side (21) of the housing (10) and a capacitive actuation sensor (51) is provided behind the or each input zone (53), said actuation sensor being connected to the control electronics. The control electronics are configured to detect predetermined sensor data of a respective one of the at least one capacitive actuation sensor (51) together with changed sensor data determined by at least one weighing sensor (41, 42) in the same time period by means of a detected weight change as input data provided for operating the kitchen appliance and to generate a corresponding control signal.

Description

[0001] TITLE

[0002] MOBILE KITCHEN APPLIANCE WITH INTEGRATED WEIGHING UNIT

[0003] TECHNICAL FIELD

[0004] The present invention relates to a mobile kitchen appliance with an integrated weighing unit, comprising: a housing in which a cover plate is provided on the upper side as a weighing surface and in which at least three feet are provided on the underside, at least three weighing sensors arranged between the housing and the feet, which are configured to record force sensor data relating to a force acting on the upper side of the cover plate, an operating device of the kitchen appliance and control electronics which is connected to the weighing sensors for recording the force sensor data and to the operating device for controlling the operating device of the kitchen appliance.

[0005] STATE OF THE ART

[0006] WO 95 / 35483 A1 discloses a cooktop with an integrated weighing function. This cooktop has a continuous surface, for example, a glass ceramic cooktop with multiple cooking zones, which serves both for cooking and as a weighing surface and can be integrated into a work surface with a frame.

[0007] DE 10 2016 221546 A1 describes a hob with a weighing function. The hob is designed to be arranged in a recess of a base plate. The hob comprises a cooking surface which is designed such that an underside of the cooking surface rests on an upper side of the base plate in an overhang region at the edge of the recess when the hob is arranged in the recess of the base plate. The hob further comprises a sensor which is configured to acquire sensor data relating to a force acting on an upper side of the cooking surface. The sensor is arranged on the underside of the cooking surface in the overhang region such that the sensor is arranged between the cooking surface and the base plate when the hob is arranged in the recess of the base plate.The sensor is a capacitive sensor that detects and reports a change in the capacitance of the sensor caused by a change in the weight of the hob and a different compression of an elastic layer.

[0008] CN 21 978 23 41 U shows a mobile cooking unit with a scale on top.

[0009] EP 4 272 614 A1 discloses a kitchen appliance with a control device for controlling the operation of the kitchen appliance and a scale for measuring the weight of food. The control device of the kitchen appliance can control the operation of the kitchen appliance depending on a pressure applied to the top of the kitchen appliance, which is detected by the scale, depending on the position of the pressure.

[0010] The kitchen appliance of EP 4 272 614 A1 may have three legs, whereby the kitchen appliance may be configured in such a way that the position of a pressure on the food preparation appliance is determined from the forces exerted on the feet and detected by the scale.

[0011] Electronic touch sensors are often used to control kitchen appliances, such as a mobile cooking stove. Depending on the design, these sensors can detect proximity, touch, and / or pressure via an electronic evaluation unit. Two types of sensors are used in particular:

[0012] • Capacitive touch sensors: These sensors are simple and very inexpensive to manufacture and account for the majority of manufactured sensors. Unlike mechanical buttons, they operate completely without pressure or force. To activate them, simply touch the sensor with a conductive or dielectric object (e.g., a finger) or even just move close to the sensor. The major advantage of these sensors is that they can be installed invisibly under a variety of materials, such as glass, foil, or plastic, and do not require any special appearance or environmental protection requirements.

[0013] • Resistive touch sensors: These sensors require not just a touch to be triggered, but a certain amount of pressure, meaning that a certain amount of force must be applied to the sensor. This can be done with a stylus, the entire finger, or even just a fingernail. Operation with gloves is no problem, and false triggering, for example, caused by water drops, can be ruled out.

[0014] There are various challenges involved in applying these technologies in the kitchen. Capacitive touch sensors are sensitive to water and other liquids. The sensor cannot distinguish between a finger and, for example, water droplets, which is very disadvantageous for kitchen applications: Malfunctions can result if, for example, a sensor is accidentally triggered due to water splashes, or an undefined state arises if several sensors are triggered simultaneously by overflowing water. Wearing kitchen gloves can make operation even more difficult or impossible. Resistive touch sensors do not have these aforementioned limitations, but cannot be hidden beneath a hard surface. The sensor requires an elastic surface, which makes the design of the corresponding appliance surfaces more complicated and more susceptible to liquids penetrating the interior of a kitchen appliance.

[0015] DE 10 2022 207 879 B3 describes a cooktop assembly with a heating device and a weighing device with at least one load cell and a weight sensor for measuring a weight load on the cooktop assembly. The cooktop assembly is integrated into a cooktop unit, which has at least three support elements at the bottom of the cooktop unit and rests on a base with these elements.

[0016] DE 10 2015 116 874 A1 discloses a method for operating a household appliance having at least one hob, a worktop, and a sensor device for detecting a force acting on the hob and / or the worktop. A sensor signal representing the force is read in. In a further step, a control signal for controlling the hob is provided using the sensor signal.

[0017] EP 4 272 614 A1 integrates a kitchen appliance with a control device for controlling the operation of the kitchen appliance and with a scale for measuring the weight of food. A control device of the kitchen appliance can control the operation of the kitchen appliance depending on a pressure applied to the top of the kitchen appliance, as detected by the scale, depending on the position of the pressure. It thus provides a user interface for controlling and operating the kitchen appliance. SUMMARY OF THE INVENTION

[0018] Based on this prior art, the invention is based on the object of making a mobile kitchen appliance equipped with an integrated weighing unit safer to operate in its cooking functions.

[0019] This task is solved in a mobile kitchen appliance equipped with an integrated weighing unit by providing at least one input zone on the top side of the housing, behind which or behind whicheach input zone is provided with a capacitive actuation sensor which is / are configured to detect respective capacitive sensor data which is / are assigned to the capacitance of the input zone (53), that the capacitive actuation sensor(s) are / are connected to the control electronics, and that the control electronics is configured to recognise - in the same period of time - changes in the measured value of capacitive sensor data of one of the at least one capacitive actuation sensors together with changes in the measured value of force sensor data detected by at least one weighing sensor due to a force acting on the upper side of the cover plate as input data provided for the operation of the kitchen appliance and to trigger a switching signal for controlling the operating device of the kitchen appliance.

[0020] In other words, in mobile kitchen appliances (e.g., a mobile cooking stove) that have an integrated weighing unit, the evaluation unit of the weighing unit is logically connected to the capacitive touch sensors located in the housing under the cover plate, creating functional added value and a new user experience. Using such a tactile sensor solution as control button(s) can achieve various advantages, in particular

[0021] • inexpensive capacitive sensors can be used, whereby a minimum required trigger pressure can be preset using the weighing unit already present in the kitchen appliance, which eliminates the biggest weakness, namely incorrect activation due to water (water drops, splashing water, overflowing water, ...) or other liquids, and

[0022] • triggering with a certain minimum force is much closer to the natural sensation of a mechanical switch and thus the correct operation of the kitchen appliance becomes more reliable and safer, regardless of whether an acoustic (e.g. beep) and / or sensory feedback (e.g. a short click-like vibration) is given to the user or not.

[0023] The force sensor data recorded by the control electronics as weight change data can originate from a group of data that includes: detection of a minimum weight change, detection of a maximum weight change, detection of a weight change within an interval between a minimum and a maximum weight change, and the increase of the recorded weight change over a predetermined actuation period between a minimum and a maximum gradient. This allows various actuation patterns to be mapped, including dynamic measurement of the weight change in addition to static limit values ​​during actuation.

[0024] The control electronics can be configured, in particular, to correlate the temporal progression of the capacitance change of an actuated sensor with the progression of the weight change detected by the weighing sensors. Typically, the capacitance change of an actuated sensor is detected first when an actuating finger approaches, before the weighing sensors detect the weight change, so that the interaction of the two sensor types allows the actuation to be determined unequivocally.

[0025] The control electronics can also be configured to differentiate between changes in the force sensor data of the weighing sensors if actuation of a predetermined actuation area results in a different load change for one or more weighing sensors compared to the other weighing sensors. If the actuation areas are located at the edge of the housing on the top, then one or two of the weighing sensors are usually subjected to a greater load than the others during actuation, so that in addition to the weight change itself, the type of weight change can also be used to decide whether to actuate the sensor.

[0026] The control electronics can also be configured to adjust the zero line of said capacitive actuation sensor to the new resting capacitance signal when the resting capacitance signal of an actuation sensor changes. This can occur if drops of liquid land in an actuation area and remain there. Then, after an adjustment period of the signal line in this area, the actuation can be reliably detected using capacitive measurement and weight measurement of the actuation. The operating device can, in particular, be at least one kitchen functional unit from the group comprising a heating element, a cooling element, an agitator, or a chopper drive. Other kitchen functional units can also be used.

[0027] As a kitchen functional unit, the operating device can, in particular, comprise at least one heating element arranged behind the cover plate in the housing. This can be a heating coil, or it can be two heating elements arranged side by side, on which separate containers filled with materials to be processed stand, the total weight of which is recorded by the scale. For cooling elements, Peltier elements, in particular, can be used behind the cover plate. Several different functional units can be combined.

[0028] If the capacitive actuation sensor(s) are arranged spatially close above or between two weighing sensors, the actuation by a user can be easily determined by the pressure distribution on the weighing sensors during actuation, as other weighing sensors do not measure any significant change in load.

[0029] Further embodiments are specified in the dependent claims.

[0030] BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Preferred embodiments of the invention are described below with reference to the drawings, which are for illustrative purposes only and are not to be construed as limiting. In the drawings:

[0032] Fig. 1 is a schematic cross-sectional view of a mobile kitchen appliance according to an embodiment of the invention, taken centrally through the kitchen appliance;

[0033] Fig. 2 is a schematic cross-sectional view of a mobile kitchen appliance according to Fig. 1 along the front side of the kitchen appliance;

[0034] Fig. 3 is a schematic plan view of the kitchen appliance according to Fig. 1;

[0035] Fig. 4 is a schematic representation of a circuit diagram of the mobile kitchen appliance according to Fig. 1 with a control circuit.

[0036] Fig. 5 is a schematic representation of general switching states of a control electronics according to Fig. 4 of the kitchen appliance according to Fig. 1; and

[0037] Fig. 6 is a schematic representation of general switching states of a control electronics according to Fig. 4 of the kitchen appliance according to Fig. 1 to avoid incorrect inputs.

[0038] DESCRIPTION OF PREFERRED EMBODIMENTS

[0039] Fig. 1 shows a schematic cross-sectional view of a mobile kitchen appliance according to an embodiment of the invention, taken centrally through the kitchen appliance. The description also refers to Fig. 2, which shows a schematic cross-sectional view of a mobile kitchen appliance according to Fig. 1 along the front of the kitchen appliance. Furthermore, Fig. 3 shows a schematic plan view of the kitchen appliance according to Fig. 1, and Fig. 4 shows a schematic representation of a circuit diagram of the mobile kitchen appliance according to Fig. 1 with a control circuit 100, wherein the other electrical or electronic elements of the kitchen appliance are designated in Fig. 4 with the same reference numerals as in Fig. 1 for the sake of simplicity.

[0040] The housing 10 of the mobile kitchen appliance comprises a cover plate 20 on its upper side. The cover plate 20 is placed on the upper side of the housing 10 and can be connected to it, in particular glued. The cover plate 20 covers the entire upper side of the housing 10. In other embodiments, only a portion of the upper side of the housing 10 can be covered by the cover plate 20.

[0041] During operation, the housing 10 is mobile and rests on a base (not shown) and is supported by feet 40. The mobile kitchen appliance with weighing unit has at least three feet 40, which then form a triangle, but can also have four feet 40, whereby one foot 40 may be height-adjustable due to the overdetermination.

[0042] Reference numerals 43 and 44 (also 41 and 42 in Fig. 2) denote weighing sensors, each arranged between a foot 40 and the housing 10 and designed to detect the weight of the housing 10 and elements arranged on the housing 10, such as a pot 60, since the entire weight rests on the associated feet 40 via these weighing sensors 41, 42, 43, 44. In other words, an up or down movement of the housing 10, possibly with the pot 60 and contents 61, is detected by the weighing sensors 41, 42, 43, 44 and forwarded to the control circuit.

[0043] A cavity is provided at least at one point below the cover plate 20 on its underside 22, in which the heating element(s) 30 (here two) and / or other functional units such as agitators, chopper drives, or others are arranged, which are connected to the control circuit 100 to be controlled thereby. At least one, here two, capacitive actuation sensors 51 and 52 are arranged beneath the cover plate 20, which react in a conventional manner to the approach of an actuation element such as a user's finger and send a corresponding control signal to the control circuit.

[0044] In contrast to conventional actuation devices using capacitive actuation sensors, in the present invention, a capacitive change is not sufficient for actuation. In this case, even the presence of a liquid droplet 54, here above the second capacitive actuation sensor 52, would trigger an actuation command in the control circuit.

[0045] Although the actuation sensors 51 and 52 are capacitive actuation sensors, the control circuit 100 is configured to only accept a change in the capacitance of the sensor 51 in the area of ​​the actuated input zone, represented here by the arrow with the reference number 53, as an actuation command if, at the same time, a significant change in weight is reported to the control circuit 100 by the weighing sensors 41 to 44. Then, for example, one or the other heating element or other functional units is turned on, off, or its power is changed. As with known built-in ceramic or induction cooktops, the usual commands can be specified by time periods, i.e., increasing the power by one point (from 1 to 9) by actuation for a predetermined period of time, such as one second.

[0046] By detecting a pressing according to arrow 53 with a predetermined weight change over a certain period of time, in particular above a minimum weight change, but advantageously smaller than a maximum weight change, by pressing on the cover plate 20 together with a detected capacitance change in the area of ​​the corresponding zone (e.g. increasing the heating power by pressing in the area 51, reducing it by pressing in the area 52), an intentional actuation can be distinguished from a liquid drop 54.In addition to detecting a pure weight change between a minimum and a maximum weight change, the increase in weight over a predetermined operating period can also be detected, i.e. the slope of the curve of the weight change versus time or the capacitance change versus time or a combination of these two dynamically derivable values ​​by the control circuit 100 in order to avoid incorrect operation due to, for example, a drop of liquid 54.

[0047] The control circuit 100 can also be connected to the sensors 51 and 52 in such a way that a temporary permanent change in capacitance, such as that caused by a drop of liquid 54, is compensated by setting a new zero line via a temporary offset, so that even with a moist operating surface above the sensors 51 and 52, it is possible to input a command to the control circuit 100, since in addition to the capacitive signal from one of the sensors 51, 52, the changed weighing signal and / or the gradient of the weight change is also used for the decision.

[0048] The cover plate 20 has a dual function. Firstly, it forms a base for a pot 60, for example a ceramic hob, which can be heated by heating elements 30. The heating elements 30 are arranged in a space of the housing 10. Secondly, the cover plate 20 forms a weighing surface onto which a pot 60 or a bowl, etc., can be placed in order to weigh it. The sensors 41, 42, 43, 44 can in particular also be capacitive sensors, in which a layer located between the capacitor surfaces is compressed by the force exerted on the cover plate 20 and thus experiences a change in the capacitor value that can be queried as sensor data. However, other weighing sensors 41, 42, 43, and 44 can also be used.

[0049] In the exemplary embodiment of Fig. 3, it can be seen that the two sensors 51 and 52 are arranged in a corner of the housing 10, in order to be located in the area of ​​the foot 40 with the weight sensor 41. It is possible that, in addition to the capacitive detection and "weighing" of a user's actuating finger (possibly via the gradient of the weight increase in a value window with a minimum and maximum gradient), the control circuit 100 also evaluates the varying load on the various sensors 41, 42, 43, 44. This "expects" that a deliberate actuation by a user will result in a higher proportion of the additional weight generated by pressing in area 53 being detected by sensor 41 compared to the sensors 42, 43, 44 of the other feet 40.

[0050] However, the movement of the housing 20 relative to the feet 40 can be restricted by guides in the vertical direction, which then does not allow the last-mentioned evaluation of the sensor data with regard to different weight data of the sensors 41 relative to the sensors 42, 43, 44, since then the sensor data of all sensors 41, 42, 43, 44 essentially detect the same force application, regardless of whether the cover plate 20 is subjected to a load at a central or non-central point of the cover plate 20.

[0051] Fig. 5 shows a schematic representation of general switching states of a control electronics according to Fig. 4 of the kitchen appliance according to Fig. 1. The reference number 91 represents the logical switching state, the reference number 92 the output value of the capacitive sensor and the reference number 93 the output value of the weighing sensor. At a first point in time, only the cover plate outside an input zone receives a contact, so that the value 70 of the (one) capacitive sensor changes, but since no value 93 of a weighing sensor changes significantly, no switching state 91 changes either. The same applies if there is a contact with force outside an input zone, since then the value 71 of the (one) weighing sensor changes, but there is no change in a capacitive sensor, so that here too no switching state 91 changes. Only if both events 70 and 71 occur will the switch according to reference numeral 72 trigger.If the load on the scale is changed by adding new material, i.e., if the value 73 changes and increases (or decreases when material is removed), a new baseline corresponding to value 73 results. The same applies if the output value of the (one) capacitive sensor 74 changes. Only when, as in the second instance, the signals from capacitive sensor 92 and weighing sensor 93 are present simultaneously and for a certain period of time, e.g., 1 second, is a switching signal triggered. This can then be triggered multiple times (or not) for longer periods.

[0052] Fig. 6 shows a schematic representation of general switching states of a control electronics according to Fig. 4 of the kitchen appliance according to Fig. 1 to prevent incorrect inputs. The events 80 and 81 correspond to the procedure in Fig. 5 for the value 92 of the capacitive sensor and the value 93 of a weighing sensor 41. The difference here is that weight changes from other weighing sensors 42 to 44 are taken into account as value 93'. If this or one of these values ​​does not change in step with the first called value 93, then no signal 82 is triggered, which is only triggered when a decentralized input zone of the cover plate or the housing with force switch is touched.

[0053] LIST OF REFERENCE SYMBOLS

[0054] 10 Housing of the mobile kitchen appliance

[0055] 20 cover plate

[0056] 21 Top of the cover plate

[0057] 22 Underside of the cover plate

[0058] 30 heating element

[0059] 40 feet

[0060] 41 foot with first weighing sensor

[0061] 42 feet with second weighing sensor

[0062] 43 feet with third weighing sensor

[0063] 44 feet with fourth weighing sensor

[0064] 51 first capacitive sensor

[0065] 52 second capacitive sensor

[0066] 53 Pressure on an input zone of the cover plate or housing

[0067] 54 Accumulation of fluid, especially water droplets

[0068] 60 pot

[0069] 61 pot contents

[0070] 63 symbolic representation of pressure on the cover plate by the pot and its contents

[0071] 70 Touching an input zone, the cover plate or the housing without force

[0072] 71 Contact of the cover plate or the housing with force outside an input zone

[0073] 72 Contact with an input zone of the cover plate or the housing with force => switch triggers

[0074] 73 Object is placed on the device (e.g. weighing item, pot, ...)

[0075] 74 Fluid accumulation on the input zone (e.g. water drops)

[0076] 80 Touching an input zone of the cover plate or housing without force

[0077] 81 Central contact of the cover plate or housing with force outside an input zone

[0078] 82 Contact with a decentralized input zone of the cover plate or the housing with force => switch triggers

[0079] 83 Incorrect contact of a decentralized input zone of the cover plate or the housing with force => switch does not trigger

[0080] 91 Switching state

[0081] 92 Value of the capacitive sensor

[0082] 93 Value of a weighing sensor (41)

[0083] 93' Value of the other weighing sensors (42 to 44) 100 Control circuit

Claims

PATENT CLAIMS 1. Mobile kitchen appliance with integrated weighing unit, comprising: a housing (10) in which a cover plate (20) is provided on the upper side as a weighing surface and in which at least three feet (30) are provided on the underside thereof, at least three weighing sensors (41, 42, 43, 44) arranged between the housing (10) and the feet (40) which are designed to record force sensor data relating to a force acting on the upper side (21) of the cover plate (20), an operating device (30) of the kitchen appliance, and control electronics (100) which is connected to the weighing sensors (41, 42, 43, 44) for recording the force sensor data and to the operating device (30) for controlling the operating device (30) of the kitchen appliance (100), characterized in that on the upper side (21) of the housing (10) at least one input zone (53) it is provided that behind the oreach input zone (53) is provided with a capacitive actuation sensor (51, 52) which is / are configured to record capacitive sensor data associated with the capacitance of the input zone (53), that the capacitive actuation sensor(s) (51, 52) are / are connected to the control electronics (100), and that the control electronics (100) is / are configured to - in the same period - detect changes in the measured value of capacitive sensor data (92; 93, 93') of one of the at least one capacitive actuation sensors (51) together with changes in the measured value of force sensor data (70, 71, 80, 81) detected by at least one weighing sensor (41, 42, 43, 44) by a force acting on the upper side (21) of the cover plate (20) as input data intended for the operation of the kitchen appliance (72, 82) and to trigger a switching signal for controlling the operating device (30) of the kitchen appliance (100).

2. Mobile kitchen appliance according to claim 1, characterized in that the force sensor data detected by the control electronics (100) as weight change data originate from the group comprising detection of a minimum weight change, detection of a maximum weight change, detection of a weight change lying in an interval between a minimum and a maximum weight change, and increase of the detected weight change over a predetermined actuation period between a minimum and a maximum gradient.

3. Mobile kitchen appliance according to claim 1 or 2, characterized in that the control electronics (100) are configured to determine the temporal course of the capacitance change of an actuated capacitive actuation sensor (51, 52) in relation to the course of the detected weight change by the weighing sensors (41, 42, 43, 44).

4. Mobile kitchen appliance according to one of claims 1 to 3, characterized in that the control electronics (100) are configured to differentiate a change in the force sensor data of the weighing sensors (41, 42, 43, 44) from one another when an actuation of a predetermined actuation range (53) leads to a different load change (93, 93') of one or more weighing sensors (41) compared to the other weighing sensors (42, 43, 44).

5. Mobile kitchen appliance according to one of claims 1 to 4, characterized in that the control electronics (100) is configured, when the resting capacity signal of a capacitive actuation sensor (51, 52) changes, to adjust the zero line of said capacitive actuation sensor (51, 52) to the new resting capacity signal (74).

6. Mobile kitchen appliance according to one of claims 1 to 5, characterized in that the control electronics (100) is configured to adjust the zero line of said weighing sensor or said weighing sensors (41, 42, 43, 44) to the new resting capacity signal (73) when the weighing signal of one, several or all weighing sensors (41, 42, 43, 44) changes.

7. Mobile kitchen appliance according to one of claims 1 to 6, characterized in that the operating device comprises at least one functional unit provided on or in the housing (10).

8. Mobile kitchen appliance according to claim 7, characterized in that the functional unit is at least one functional unit from the group comprising a heating element, a cooling element, an agitator or a chopper drive.

9. Mobile kitchen appliance according to claim 8, characterized in that the functional unit comprises a heating element (30) or cooling element arranged behind the cover plate (20) in the housing (10) for operation.

10. Mobile kitchen appliance according to one of claims 1 to 9, characterized in that the capacitive actuation sensor(s) (51, 52) are arranged spatially close above one or between two weighing sensors (41 to 51, 42 to 52).

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