ES2933029T3 - Induction cooking field device - Google Patents

Abstract

The invention is based on a cooking device, in particular an induction cooking device, with at least one capacitive sensor unit (10a; 10b). In order to provide a generic device with advantageous properties with respect to capacitive detection of an object, it is proposed that the sensor unit (10a; 10b) have at least one sensor surface (12a; 12b) with at least one open conductive track (14a; 14b). (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Induction cooking field device

The present invention relates to an induction cooking range device according to the preamble of claim 1, and to a method with an induction cooking range device according to the preamble of claim 12. Through the state of the art , induction cooking range devices are already known which allow any positioning of the cookware on a cooking range plate. These partly have movable induction coils which can be moved laterally under the cooktop into a position for placing the cookware. In this connection, a determination of the laying position takes place via a grid of the cooking range plate by means of the moving induction coils, which uses at least some in which the induction cooking range device does not is still available to heat the cookware.

From DE 19648 199 A1, a device is known for connecting electrical conductive tracks provided next to a glass-ceramic cooking area to connection lines.

From DE 196 46 826 A1, a method for detecting a heatable cooking pot on a glass-ceramic hotplate with a capacitive sensor installed next to the hotplate, an oscillating circuit and a temperature sensor is known.

From DE 4336752 A1, a method is known for adapting the electrical heating power to the parameters required for food preparation.

The object of the invention consists in particular in providing a generic device with advantageous properties as regards capacitive recognition of an object. According to the invention, this object is achieved by the characterizing features of claims 1 and 12, while advantageous embodiments and improvements of the invention can be derived from the dependent claims.

The invention relates to an induction cooking range device, with at least one capacitive sensor unit.

It is proposed that the sensor unit has at least one sensor surface with at least one open conductive track.

By "planned" must be understood in particular programmed, conceived and/or provided in a specific way. The fact that an object is provided for a certain function is to be understood in particular that the object satisfies and/or performs this certain function in at least one application and/or operating state. By "induction cooking range device" is to be understood in this particular context at least a part, in particular a subassembly, of an induction cooking range. The induction cooking range device can in particular also comprise the entire induction cooking range. By "sensor unit" is to be understood in this particular context a unit that is intended to record at least one parameter and/or physical property, where the recording can take place actively, such as by generating and emitting an electrical signal of measurement, and/or passively, such as by detecting changes in the properties of a sensor component. "Capacitive sensor unit" is to be understood as a sensor unit with at least one electrode that is provided for the generation of a sensor signal from a change in an electric field and/or a change in capacitance. Advantageously, the capacitive sensor unit is provided for recognizing an approach of at least one object, in particular a user's finger and/or, advantageously, a cooking battery, and/or a contact through at least one object, specifically through a user's finger and/or, advantageously, through a cooking battery. In a particularly advantageous manner, the sensor unit generates a particularly electronic signal, in particular a digital signal, which is provided for further processing by a computing unit. Preferably, the capacitive sensor unit is provided for the recognition of an object, in particular a cooker, placed or resting on and/or on top of the sensor unit.

In this context, "sensor surface" is to be understood in particular as a sensor subunit that has at least one physical parameter that changes measurably in the event of direct contact with an object to be detected and/or in the event of an approach of a object to recognize Advantageously, at least the capacitance of at least one capacitor, which is at least partly formed by at least a part of the sensor surface, changes depending on an approximation of at least one object, in particular a finger of a user and/or, advantageously, a cooking battery, and/or depending on a contact through at least one object, in particular through a user's finger and/or, advantageously, through through a cooking battery. Particularly advantageously, the part of the sensor surface or the entire sensor surface forms an electrode of the capacitor. Specifically, the sensor surface is formed by the conductive track and by the intermediate spaces enclosed by the conductive track. Advantageously, the sensor surface is designed to be at least substantially flat. In a particularly advantageous manner, the sensor surface follows at least essentially the shape of an ellipse, in particular of a circle, or the shape of a rectangle, in particular of a square, or the shape of a hexagon, in particular of a regular hexagon. . The area of the sensor surface is in particular not more than 400 cm2, preferably not more than 100 cm2, particularly preferably not more than 25 cm2, advantageously not more than 1 cm2, particularly advantageously not more than 1 mm2. In this context, "conductive track" is to be understood in particular as an electrically conductive element which, in particular in an imaginary, unwound state, has a length that is at least 10 times, preferably at least 100 times and, particularly advantageously, at least 1,000 times greater than its width and thickness. In a particularly advantageous manner, the conductive track has an at least essentially constant cross section whose area varies in total along the length by, in particular, a maximum of 20%, preferably a maximum of 10% and, particularly advantageously, in 5% maximum, namely an at least essentially rectangular at least essentially constant cross section. Preferably, the conductive track runs at least essentially in one conductive track plane. In a particularly preferred manner, the thickness of the conductive track runs parallel to a normal to the surface of the conductive track plane. Also, the width of the conductive track extends in particular perpendicular to the surface normal of the conductive track plane. The conductive track is made of concrete at least partly and preferably entirely of metal. Preferably, the conductive track is made as a track on an electrical board. However, it is also conceivable that the conductive track is made in particular as a metal filament. It could also be conceivable that the conductive track is designed as a cover on and/or below a cooking range plate of the induction cooking range device. By "open conducting track" is to be understood a conducting track along whose layout only open paths can be written. Preferably, the diameter of the largest circular path that can be inscribed in a projection of the conductive track onto the plane of the conductive track corresponds to the maximum width of the conductive track. The conductive track has at least one open end. The conductive track is in electrical contact with at least one other end, in particular via at least a part of the sensor unit, preferably via permanent electrical contact.

Through the embodiment according to the invention, a rapid recognition of objects is made possible in particular, with simultaneously reduced electrical power losses. An induction cooking field device according to The invention makes possible, in particular, a rapid recognition of objects resting on or placed on a household appliance. Advantageously, it is possible to detect a resting position of the cookware during operation of an induction coil. In a particularly advantageous manner, the power losses during operation of the induction coil can be reduced. Specifically, it is possible to detect the placement positions of several supported objects at the same time. Advantageously, the type of objects can be recognized. Specifically, it is possible to recognize whether an object is a cooking battery. Preferably, targeted heating of the detected objects is possible, in particular heating of suitable cookware only. In this way, in particular, the induction of eddy currents on the sensor surface by the alternating magnetic field of the induction heating units can be reduced. Advantageously, the sensor unit can be prevented from influencing the impedance of an induction coil.

Furthermore, it is proposed that the conductive track have at least one first conductive track section and at least one second conductive track section, which extend with an at least essentially constant distance from one another. By "conductor track section" is to be understood in this context in particular a partial fragment of the conductive track, in particular a partial fragment made in one piece with the conductive track. Preferably, the section of the conducting track has a linear outline, or is made as a circular section or as a curved section without a turning point. It is also conceivable in particular that the conductive track section follows a spiral path less partially. Preferably, the conductive track section then follows a curvature of a maximum of 360° in total, where there is a junction of two conductive track sections, specifically at a point of intersection of the conductive track with an imaginary line running concentrically to the left. spiral. By "at least essentially" is to be understood in this particular context that a deviation differs from a particular predetermined value by less than 15%, preferably by less than 10% and particularly preferably by less than 5% of the default value. In this way, a conductive track arrangement of simple construction can be advantageously achieved. Also, the conductive track can advantageously form a planar structure.

In addition, it is proposed that the conductive track have at least a first conductive track section and at least a second conductive track section, which at least partially envelops the first conductive track section when viewed parallel to a normal of the surface of the sensing surface. With respect to at least a large part of the points on a projection of the first conductive track section onto the sensor surface, in particular in each case there is a straight line through the corresponding point, which lies perpendicular to a tangent to the path of the conductive track section at the point and perpendicular to a surface normal of the sensing surface at the point, and which runs through at least one point on a projection of the second conductive track section onto the sensing surface. Advantageously, the two conductive track sections extend in a common plane. In a particularly advantageous manner, the conductive track follows an intricate path. The conductive track can be designed in particular in the form of a labyrinth. In this way, a flat electrode of a capacitor can advantageously be formed by a particular conductive track. Thus, it is possible in particular to reduce power losses in an alternating magnetic field through induced eddy currents.

In a preferred embodiment of the invention, it is proposed that the conductor track has at least one branch. "Branch" is to be understood in this context in particular as an area of the conducting track in which at least two mutually different conducting track sections touch and/or intersect. Preferably, the tangents of the conductive track sections intersect in the branch. In this way, a surface can be advantageously crosslinked by the layout of the conductive track. Furthermore, in particular power losses during operation in an alternating magnetic field can be reduced.

In a particularly preferred embodiment of the invention, it is proposed that the total area of a projection of the conductive track on the sensor surface is at least 5%, specifically at least 10%, preferably at least 20%. , preferably at least 30%, particularly preferably at least 40%, advantageously at least 50% and particularly advantageously at least 60% of the total area of the smaller quadrangle surrounding the projection , of the smallest hexagon that surrounds the projection, or of the smallest ellipse that surrounds the projection. Preferably, the layout of the conductive track at least partially grids an ellipse, in particular a circle, or a sector of an ellipse, in particular a sector of a circle, or a rectangle, in particular a square, or a hexagon, in particular a regular hexagon. In this way, a surface of a non-crossing planar geometric figure can advantageously be formed by the conductive loop. Also, a condenser electrode of simple construction can advantageously be implemented in this way. In particular, several sensor surfaces can advantageously be compactly packed in one plane.

Furthermore, it is proposed that the maximum width of the conductive track is 4 mm, in particular 2 mm, preferably 1 mm, particularly preferably 500 pm and advantageously 100 pm. Furthermore, the maximum thickness of the conductive track is in particular 4 mm, advantageously 2 mm, preferably 1 mm, particularly preferably 500 pm and particularly advantageously 100 pm. In this way, the induction of large eddy currents can be advantageously avoided. Likewise, power losses due to induction currents can be advantageously reduced.

The at least one sensor surface has at least one other open conductive path. Advantageously, the conductor track and the other conductor track run at least essentially in a common plane. In particular, the other conductor track can be designed as a shielding conductor track, which is provided in particular for shielding against electromagnetic disturbances. Preferably, the other conductive track is provided to reduce fluctuations caused by the environment in a potential of the conductive track. In this way, a simple construction of a sensor surface with a high measurement accuracy can be advantageously achieved.

In at least one operating state, the other conductive track is at a different potential relative to the conductive track. Advantageously, the other conductive track is electrically connected to a ground. In the event of a contact with the sensor surface and/or a pressure on the sensor surface, a capacitance measurement is carried out during which the conductive track acts as the first electrode of a measuring capacitor which is shielded by the other conductive track with respect to parasitic signals from the environment. In this way, the accuracy of a capacitance measurement can be advantageously improved. In addition, in this way erroneous measurements due to contact or pressure can be advantageously avoided.

In a particularly preferred embodiment of the invention, it is proposed that the other conductor track surrounds the conductor track at least essentially when viewing parallel to a surface normal of the at least one sensor surface. Specifically, a ray for at least a large part of all the points on the circle, which extends radially from the center point of the smallest common circle of the projection of the conducting track and of the projection of the other conducting track on the surface. Sensing out through a point on the circumference, it cuts last to the other conductive track, viewed from the center point. In this way, a particularly effective shielding effect can advantageously be achieved. In addition, an easy-to-connect common shielding of an arrangement with several sensor surfaces can advantageously be achieved in this way.

Advantageously, the total area of a projection of the conductive track and of the other conductive track on the sensor surface is at least 5%, in particular at least 10%, preferably at least 20%, preferably at least 30%, particularly preferably at least 40%, advantageously at least 50% and particularly advantageously at least 60% of the total area of the sensor surface. Thus, a sensor surface can advantageously be formed essentially by conductive tracks. In addition, this can advantageously provide an electromagnetically shielded sensor surface for low-loss operation in an alternating magnetic field.

Advantageously, the induction cooking range device comprises at least one cooking range plate that is provided to support at least one cooking battery, and at least one induction coil arranged below the cooking range plate, where the sensor surface is arranged in at least one state of operation between the cookware and the induction coil. By "cooking range hob" is to be understood in particular a hob unit on which the hob can be placed, in particular a pot, frying pan and/or the like, preferably for heating. The cooking range plate has in particular a resistance to elevated temperatures, specifically at least up to 300°C, advantageously at least up to 400°C. The cooking range plate has in particular a quantitatively low coefficient of linear thermal expansion, specifically less than 1 • 10-6 K-1, advantageously less than 510-5 K-1, preferably less than 1 • 10 -5K-1. The term "induction coil" is to be understood in particular as a wound electrical conductor, preferably in the form of a circular plate, through which high-frequency alternating current flows through it in at least one operating state. Preferably, the induction coil is provided for generating an alternating magnetic field by transforming electrical energy, which is intended to cause eddy currents in a heating medium, in particular a metallic, preferably at least partly ferromagnetic cooking battery. and/or magnetic reversal effects that are transformed into heat. The induction cooking range device has in particular several sensor surfaces arranged next to each other. Advantageously, the sensor unit has a sensor matrix formed by several regularly arranged sensor surfaces next to each other, the total surface of which corresponds at least essentially to the total surface of the cooking range plate. Advantageously, the sensor surfaces of the matrix are packed in an at least essentially compact manner. The sensor array is provided in particular for recognizing the position and/or shape of an object resting on and/or placed on the hob. Preferably, the induction cooking range device is intended to heat a cooking battery resting at any point on the cooking range plate. In this way, it is possible to advantageously recognize a position for placing the cookware on the cooking area plate. In this way, it is also advantageously possible to recognize an area of the cooking range plate in which heating is to take place. In this way, it is possible, in particular, to prevent heating of objects made differently from the cooking battery, such as knives, ladles, etc., placed or supported by mistake.

Preferably, the induction cooker device comprises at least one transport unit, which is provided to move the at least one induction coil at least substantially parallel to the cooker plate. Concretely, in each case at least one induction coil can be moved under at least a large part of all the points of the hob. As an alternative, however, it is also conceivable in particular that an induction coil array of several induction coils is arranged below the cooking area, which is provided for a possible heating of at least a large part of all points. of the cooktop. In this way, in particular, heating can advantageously be carried out at any position on the cooking range plate with a high degree of efficiency. In addition, it is thus possible advantageously to start heating up very quickly after inserting a cookware.

It is proposed that a placement position of the cookware on the cooking range plate is determined by the sensor unit. The sensor unit is intended in particular for recognizing the shape of an object supported and/or placed on the cooking field plate. In this case, the spatial resolution is in particular at least 10 cm, preferably at least 5 cm, particularly preferably at least 2 cm, advantageously at least 1 cm, particularly advantageously at least 1 mm .

By means of a method according to the invention, a rapid recognition of objects is made possible in particular, with simultaneously reduced electrical power losses. In this way, it can be advantageously recognized whether a supported and/or placed object is a cooking battery. In addition, an area of the cooktop necessary for heating a cookware set on top can advantageously be quickly activated. Furthermore, it is possible to advantageously avoid unnecessary operation of the cooking range plate. In this way, a particularly high degree of efficiency can be achieved.

Show:

1 shows a part of an induction cooking range with a cooking range device, in schematic cross-sectional representation,

2 a sensor array of a capacitive sensor unit of the cooking range device, in schematic top view,

3a a sensor surface of a capacitive sensor of the sensor array with at least one open conductive track, in schematic top view,

3b a section of the sensor surface of a capacitive sensor, in schematic top view, FIG. 4 a sensor surface of an alternative cooking area device, in schematic top view.

1 shows a part of a cooking range 36a configured as an induction cooking range with a cooking range device, represented in a side section. The cooking range device has a cooking range plate 24a, on which is supported a cooking battery 26a designed as a pot. In the present case, the hob 24a is designed as a glass ceramic hob. The cooking range device comprises a capacitive sensor unit 10a arranged below the cooking range plate 24a, by means of which a setting position of the cookware 26a with a base plate 70a can be recognized with spatial resolution. An induction coil 60a of the cooking range device is arranged below the sensor unit 10a, which is connected to a transport unit 62a of the cooking range device which has a swivel arm 68a. By means of the transport unit 62a, the induction coil 60a can be moved in a plane parallel to the cooking field plate 24a. The cooking range device can in particular have several such induction coils and transport units, so that heating is possible over at least a considerable part of the surface area of the cooking range plate 24a. In this way, a cookware 26a supported in any setting position on the cooking area 24a can be heated in the setting position after an induction coil 60a has been moved into the setting position. It is also possible, in particular, to recognize and heat simultaneously different cookware supported in different laying positions.

2 shows a schematic top view of the sensor unit 10a, which in the present case has a sensor array 56a with 120 sensor surfaces 12a. The sensor array 56a has an area of approximately 800 x 660 mm2. By evaluating the measurement signals of the different sensor surfaces 12a, a determination of the relative position of an approximation of an object on the sensor array 56a is possible. Likewise, both the size and the shape of an object resting on it can be recognized. In this regard, the spatial resolution is in particular dependent on the number of sensor surfaces 12a per unit. sensor array surface 56a. Other numbers of sensor surfaces 12a of the sensor array 56a are conceivable, for example a number of about 200 or, for example, a number of about 500 or, for example, a number of about 1,000 or , by way of example, a number of about 5,000 sensor surfaces. In this respect, the sensor surfaces 12a can also be arranged in a way other than that shown in the sensor array 56a, for example as the most compact circular packing in the case of circular sensor surfaces, as an orthogonal lattice. in the case of rectangular sensor surfaces, or as a honeycomb structure in the case of hexagonal sensor surfaces.

3a shows one of the sensor surfaces 12a, which has an open conductive path 14a, in schematic top view. In the present case, the sensor surface 12a is designed to be at least essentially circular. However, other shapes of the sensor surface are also conceivable, such as an elliptical sensor surface, a rectangular sensor surface, in particular a square sensor surface, or a hexagonal sensor surface, in particular a regular hexagon-shaped sensor surface. . In the present case, the sensor surface 12a has a diameter of approximately 5 cm. Likewise, the maximum width of the conductive track 14a is approximately 1 mm in the present case and the maximum thickness of the conductive track 14a is approximately 100 pm. However, it is also conceivable that the sensor surface 12a has a different diameter and that, correspondingly, the conductive track 14a has a different width, with a geometry essentially unchanged in other respects. By way of example, the diameter of the sensor surface 12a could be, for example, 1 cm and the width of the conductive track 14a 200 pm correspondingly. It is also conceivable that the maximum thickness of the conductive track 14a is also configured differently than 100 pm. Thus, the maximum thickness of the conductive track 14a could be, for example, 50 pm or 10 pm. Consequently, a cross section of the conductive track 14a can be adapted in a concrete way corresponding to the total area of the sensor surface 12a. In the present case, the conductive track 14a is made at least basically of copper. However, conductive tracks made of other metals, such as aluminum, brass, iron, stainless steel, magnesium, silver, gold, or various copper alloys, are also conceivable. In particular, conductive tracks made of a conductive polymer such as PEDOT:PSS, in particular conductive tracks applied by means of a printing technique, are also conceivable.

The conductive track 14a follows a spiral path in sections, which at least essentially describes the shape of two circle sectors 48a, 50a connected at the center. The conductor track 14a is arranged on a base plate 70a of the sensor unit 10a, and has a contact point 64a through which the conductor track 14a can be contacted via the base plate 70a. The conductive track 14a has at least one first conductive track section 16a and at least one second conductive track section 18a, which extend with an at least essentially constant distance from one another. The second conductive track section 18a encircles the first conductive track section 16a at least partially when viewed parallel to a surface normal of the sensor surface 12a. In the present case, the first conductive track section 16a and the second conductive track section 18a each describe a curve, wherein the radius of the curve of the second conductive track section 18a is greater than the radius of the curve of the first conductive track section 16a to such an extent that the two conductive track sections 16a, 18a extend with an at least essentially constant distance from one another. In the present case, the route of the two conductive track sections 16a, 18a follows in each case specifically a circular section in each case one of two concentric circles.

The total area of a projection of the conductive track 14a onto the sensor surface 12a amounts to approximately 10% of the total area of the smaller flat, non-crossing hexagon 74a surrounding the projection (FIG. 3b). In the area of the contact point 64a, the hexagon 74a has two opposite non-convex angles and surrounds to each of the two circle sectors 48a, 50a with three sides in each case, whereby a convex angle of the hexagon 74a lies in each case in the area of the outer corners of the circle sectors 48a, 50a. Consequently, the conductive track 14a forms an essential part of a first electrode surface 72a. In the case of approaching an object, it can therefore be caused that the total capacitance is changed in a safe manner and that a change in the capacitance is detectable.

The sensor surface 12a has a further open conductor track 22a, which is at a different potential than the conductor track 14a in at least one operating state. In the present case, the other conductive track 22a also follows a spiral path, and is connected to ground through a contact point not shown. The other conductor track 22a acts as a shield for the conductor track 14a during a capacitance measurement. During such a capacitance measurement, the conductive track 14a is then at a different potential from the ground potential. In the case of observation parallel to a normal of the surface of the at least one sensor surface 12a, the other conductor track 22a surrounds the conductor track 14a at least essentially. The conductive track 14a and the other conductive track 22a extend at least essentially in a common plane. The other conductive track 22a has an annular conductive track section 52a, which surrounds the conductive track 14a at least essentially and delimits the sensor surface 12a at least substantially to the outside. The annular conductive track section 52a has an interruption 54a so that the induction of eddy currents in the annular conductive track section 52a can be attenuated, for example, by alternating magnetic fields of a cooking range coil by induction. However, the interruption 54a is small compared to the diameter of the sensing surface 12a, so that the other conductive track 22a can effectively shield the conductive track 14a against electromagnetic disturbances.

In the present case, the maximum width of the further conductive track 22a is approximately 1 mm and the maximum thickness of the further conductive track 22a is approximately 100 pm. However, it is also conceivable that the other conductive track 22a has a different width, with a geometry essentially unchanged in other respects. The width of the other conductive track 22a could be, for example, 500 pm or 100 pm. It is also conceivable that the maximum thickness of the further conductive track 22a is also configured differently than 100 pm. Thus, the maximum thickness of the other conductive track 22a could be, for example, 50 pm or 10 pm. Consequently, a cross section of the other conductive track 22a can be precisely adapted in a corresponding way to the total area of the sensor surface 12a. In the present case, the other conductive track 22a is at least basically made of copper. However, conductive tracks made of other metals, such as aluminum, brass, iron, stainless steel, magnesium, silver, gold, or various copper alloys, are also conceivable. In particular, conductive tracks made of a conductive polymer such as PEDOT:PSS, in particular conductive tracks applied by means of a printing technique, are also conceivable.

The total area of a projection of the conductive track 14a and of the other conductive track 22a on the sensor surface 12a is in the present case approximately 10% of the total area of the sensor surface 12a. Therefore, the sensor surface 12a is formed in a considerable part by the conductive track 14a and the other conductive track 22a. The conductive track 14a and the other conductive track 22a in each case form a considerable part of a flat electrode, thus making it possible to precisely detect an approach of an object. By designing the sensor surfaces 12a of the sensor array 56a, circular currents induced by an alternating magnetic field that arise during operation of the induction coil 60a can be prevented at the sensor surfaces 12a of the sensor array 56a. . Consequently, the placement position of the cookware 26a can be detected without errors even during heating of the cookware 26a. In addition, electrical losses are reduced and the degree of efficiency is increased.

In figure 4, another embodiment of the invention is shown. The following descriptions are limited essentially to the differences between the exemplary embodiments , where, with regard to components, features and functions that remain the same, reference can be made to the description of the exemplary embodiment of Figures 1 to 3. For the differentiation of In the embodiment examples , the letter "a" of the reference symbols of the embodiment example of Figures 1 to 3 has been replaced by the letter "b" in the reference symbols of the embodiment example of Figure 4. Regarding with components indicated in the same way, in particular as regards components with the same reference symbols, reference can also be made basically to the drawings and/or the description of the exemplary embodiment of FIGS. 1 to 3.

Figure 4 shows an alternative sensor surface 12b in schematic top view. The sensor surface 12b has an open conductive track 14b, which covers an essentially circular surface and has a contact point 64b, through which the sensor surface 12b can be contacted via a base plate. Likewise, the conductive track 14b has at least one branch 20b. In the present case, the conductive track 14b has at least a first conductive track section 16b and at least a second conductive track section 18b, which at least essentially follow the paths of two concentric circles. The layout of the first conductive track section 16b and the layout of the second conductive track section 18b are configured other than closed circles. The conductive track sections 16b, 18b have in particular interruptions 58b, 66b, so that the induction of eddy currents in the conductive track sections 16b, 18b can be prevented, for example by alternating magnetic fields of a coil. of the induction cooking range.

The sensor surface 12b has a further open conductive track 22b, which serves as a grounded electrode in the case of capacitance measurement. The conductive track 22b is multi-branched and surrounds the conductive track 14b at least essentially when viewed parallel to a surface normal of the sensor surface 12b, so that effective shielding of the conductive track can be achieved. 14b against parasitic electromagnetic signals.

Reference symbols

sensor unit

sensing surface

conductive track

conductive track section

conductive track section

Branch

another conductive track

cooking field hob

cooking battery

cooking range

circle sector

circle sector

conductive track section

Interruption

sensor array

Interruption

induction coil

transport unit

Contact point

Interruption

pivoting arm

base plate

electrode surface

Hexagon

Claims (12)

1. Induction cooking range device with at least one capacitive sensor unit (10a), wherein the sensor unit (10a) has at least one sensor surface (12a; 12b) with at least one open conductive track (14a; 14b) along whose path only open paths can be written, where the conductive track has at least one open end and is in electrical contact with at least one other end, where the sensor surface (12a; 12b) has at least one other conductive track (22a ; 22b) open along whose path only open trajectories can be written, characterized in that, in at least one operating state, the other conductive track (22a; 22b) is at a different potential with respect to the conductive track ( 14a; 14b) and, in the event of a contact with the sensor surface (12a; 12b) and/or a pressure on the sensor surface (12a; 12b), a capacitance measurement occurs during which the conductive track ( 14a; 14b) acts as the first electrode of a measurement capacitor and the other conductive track (22a; 22b) shields the conductive track (14a; 14b) from interference signals from the environment. Induction cooking range device according to claim 1, characterized in that the conductive track (14a; 14b) has at least one first conductive track section (16a; 16b) and at least one second conductive track section (18a ; 18b), which extend with an at least essentially constant distance from each other. Induction cooking range device according to claim 1 or 2, characterized in that the conductive track (14a; 14b) has at least one first conductive track section (16a; 16b) and at least one second conductive track section (18a; 18b), which at least partially surrounds the first conductive track section (16a; 16b) in case of observation parallel to a surface normal of the sensing surface (12a; 12b). Induction cooking range device according to one of the preceding claims, characterized in that the conductive track (14b) has at least one branch (20b). Induction cooking range device according to one of the preceding claims, characterized in that the total area of a projection of the conductive track (14a; 14b) onto the sensor surface (12a; 12b) is at least 5% of the total area of the smallest uncrossed planar quadrangle surrounding the projection, of the smallest uncrossed plane hexagon (74a) surrounding the projection, or of the smallest planar ellipse surrounding the projection. Induction cooking range device according to one of the preceding claims, characterized in that the maximum width of the conductive track (14a; 14b) is 4 mm. Induction cooking range device according to one of the preceding claims, characterized in that the other conductive track (22a; 22b) surrounds the conductive track (14a; 14b) at least essentially when viewed parallel to a normal one of the surface of the at least one sensor surface (12a; 12b). Induction cooking range device according to one of the preceding claims, characterized in that the total area of a projection of the conductive track (14a; 14b) and of the other conductive track (22a; 22b) on the sensor surface ( 12a; 12b) amounts to at least 5% of the total area of the sensor surface (12a; 12b). Induction cooking range device according to one of the preceding claims, characterized by at least one cooking range plate (24a) which is provided to support at least one cooking battery (26a, 28a, 30a), and by least one induction coil (60a) arranged below the cooking area plate (24a), where the sensor surface (12a; 12b) is arranged in at least one operating state between the cooking battery (26a, 28a, 30a ) and the induction coil (60a). Induction cooking field device according to claim 9, characterized by at least one transport unit (62a) which is provided to move the at least one induction coil (60a) at least substantially parallel to the field plate cooking (24a). Induction cooking range (36a) with at least one induction cooking range device according to one of the preceding claims. 12. Method with an induction cooking range device that is intended to support at least one cooking battery (26a, 28a, 30a), with at least one induction coil (60a) arranged below the cooking range plate (24a), and with at least one capacitive sensor unit (10a) with at least one sensor surface (12a; 12b) having at least one open conductive track (14a; 14b) along whose path only open paths can be written , where the conductive track has at least one open end and is in electrical contact with at least one other end, where the sensor surface (12a; 12b) is arranged in at least one operating state between the cooking battery (26a, 28a, 30a) and the induction coil (60a), where a placing position of the cookware (26a, 28a, 30a) on the cooktop (24a) is determined by the sensor unit (10a), where the sensor surface (12a; 12b) presents at least one other conductive track (22a; 22b) open along whose path only open trajectories can be written, characterized in that, in at least one operating state, the other conductive track (22a; 22b) is at a different potential with respect to the conductive track (14a ; 14b) and where, in the event of contact with the sensor surface (12a; 12b) and/or pressure on the sensor surface (12a; 12b), a capacitance measurement is carried out during which the conductive track ( 14a; 14b) acts as the first electrode of a measuring capacitor which is shielded by the other conductive track (22a; 22b) from interference signals from the environment.