EP1758431B1 - Electronicallly controlled cooktop with several cooking fields and the controlling method of such cooking fields - Google Patents

Description

The invention relates to an electronically controlled cooktop with a plurality of cooking zones according to the preamble of claim 1 and a method for operating such a cooktop.

To operate, for example, hobs, it is known to use as controls various switches, such as mechanical pressure switch or so-called touch switch. This makes it possible, on the one hand, to switch the entire hob on or off. Furthermore, operating functions can be carried out on the cooktop with it, for example a selection of a hotplate or a change of their power level.

The EP 967 839 A2 describes how, by moving a cooking pot placed on a cooking plate, a power level for a corresponding Heating device can be adjusted. This displacement of the cooking pot is detected by capacitive sensor elements. By shifting in one direction, one power level can be increased, and by shifting in the other direction, the power level can be lowered.

Task and solution

The invention is based on the object to provide an aforementioned cooktop and an aforementioned method with which problems and disadvantages of the prior art can be avoided and hobs and their operation can be further developed advantageous, in particular an operating function on the hob improved way can be done.

This object is achieved by a hob with the features of claim 1 and by a method having the features of claim 11. Advantageous and preferred embodiments of the invention are the subject of further claims and are explained in more detail below. The wording of the claims is made explicit reference to the content of the description. Some features concerning the hob and the process are described only once in the following. However, they apply independently and generally for both the hob and the process.

According to the invention, it is provided that the hob has a control and at least one actuation sensor, wherein the actuation sensor recognizes the setting up of a cooking vessel or touching a cooking vessel erected on the hob or a cooking area. This recognition advantageously takes place in that an operator touches the cooking vessel, which must be metallic for this purpose, and thus makes electrical contact, or thus, so to speak, switches in series to the cooking vessel. The actuation sensor and the controller are designed such that the touch of a cooking vessel on a hotplate, regardless of whether the cooking vessel was already on it or has just been set up, is detected by an operator and interpreted as an operation on the hob or is valued. This forms the set up on a hotplate Cooking vessel together with the actuation sensor on the hob a touch switch for an operator, as it can be used to operate the hob with a corresponding operating function or is known in other ways from the prior art.

Thus, it is possible by the invention to turn on by the novel touch of the cooking vessel, the hob or certain functions to cause or trigger and not only by special and usual provided on the hob switches or other controls. It is also very comfortable possible, for example, by setting up a cooking vessel on a particular hob of the off cooktop this turn on. It may be secondary, whether the cooking vessel must first be placed on the hotplate or an already placed cooking vessel is touched. Finally, the hob or actuator detects that a cooking vessel is being touched. If this is done according to a possibly provided pattern, it is understood as an operating function in the sense of switching on the hob. Likewise, it is possible, alternatively to switching on the hob by touching a set-up cooking vessel or setting up such to a hotplate to select or select this hotplate.

The advantage here is above all that it is not only possible in this way to save a control. Such a possibility of operating a hob can in fact be very intuitive or configured. If, for example, a cooking vessel is exposed to a hotplate of a hob, usually the beginning of a cooking process is intended. If it is now possible with the invention, by setting up the cooking vessel to turn on the hob immediately or under certain circumstances immediately select the appropriate hotplate for a possible subsequent power setting, so a cooking process can be started very quickly. Above all, this happens in a very well adapted to the actions of the operator way.

Thus, for example, a switch on or a selection of the cooking zones to be changed happens almost automatically or by itself. In addition to the saving effect of an ON / OFF switch or a selection switch, an operator can be facilitated the operation in many cases.

As actuation sensors basically different types of sensors can be used, which detect the touching of the cooking vessel. This can be a so-called capacitive sensor, as it is for example in the DE 42 24 934 A is described. Alternatively, it may be an inductive sensor, which may, for example, have a coil shape and in which DE 196 03 845 A is disclosed. Furthermore, it is possible that an actuation sensor detects a slight movement of the cooking vessel, for example a slight back and forth by a few centimeters. Such a process, in addition to conventional methods described above, by optical sensors or the like. Above the hob and sensors for vibration or acceleration can be detected under the hob.

In a preferred embodiment of the invention, an actuation sensor may simultaneously be a so-called cooking vessel detection sensor, also known as cooking vessel detection or pan detection. Through this dual function, the number of sensors to be provided can be reduced. In this sense, it is therefore advantageous if the presence of a cooking vessel as well as a touch of the same is detected by the same measuring method. The different operating modes of the sensors can, for example, take place alternately.

It is advantageous if the actuation sensor is arranged below the hob or a hob plate. So he does not disturb the appearance, is easy to install or provide on the hob and is also odgl from deterioration such as pollution. protected. Such a hob plate is advantageously made of glass ceramic, which is permeable to the aforementioned sensors.

In one embodiment of the invention, even more actuation sensors may be provided per hotplate. These are advantageously arranged at different positions. Thus, an adaptation to possible different sizes of a cooking vessel can take place on this cooking point, for example in a multi-circuit heating. The plurality of actuation sensors can be arranged in cooperation with possible sizes of the cooking vessel so that depending on the size of the cooking vessel only one actuation sensor responds to the touch of a cooking vessel.

In a further development of the invention, it can be provided that the hob or the controller are designed so that several or different operating functions of the hob can be made via the operating sensor with contact of the cooking vessel by an operator. This concerns, for example, the switching on of the hob as well as possibly a selection function of a hotplate for subsequent, hob-specific settings such as power, additional heaters or timer functions.

Furthermore, it can be provided according to the invention that common operating elements are provided for the operator-dependent change of the operating state of the cooking area, for example a setting of a power, which have the function assigned to them exactly the same for all cooking zones. Advantageously, these are a so-called Plus and one minus control, with which the power can be increased or decreased continuously or in steps. If the hob is switched on by setting up a cooking vessel or touching a raised cooking vessel, it is ready for use. If a hotplate is subsequently selected by touching the cooking vessel placed thereon, then the common operating elements are aligned with this hotplate or their function changes the operating state of this hotplate. It can also be provided that by setting up or touching a cooking vessel, the hob is turned on and at the same time, so without further contact, the hotplate on which the touched cooking vessel is selected.

It can be provided that by appropriate signal devices or the like. a feedback is issued to an operator indicating a selection state or a change in the operating state of a cooking station. If, for example, the hob is switched on, feedback can be sent to the operator. This can be optical or acoustic, advantageously both.

To increase the operating safety by the function of the invention can be provided that for effecting the operating function a cooking vessel must be touched several times. In the context of this, it can also be provided to encode or mark, as it were, different operating functions by means of a different number of necessary contacts or their type, for example via long or short contact times and pauses of varying lengths, and trigger them differently. Thus, it is possible, for example, to be able to switch on the hob according to the invention only when a placed cooking vessel is touched twice or three times. Advantageously, such a multiple touch occurs within a certain predetermined maximum time. This makes it possible to rule out incorrect operation. These would be particularly related to Turning the hob very disadvantageous and should be avoided if possible.

As a further security feature can be provided that only then an operation is recognized as such when a standing on the hotplate or placed thereon cooking vessel is touched for a certain time. This time should also be in the range of seconds, preferably at least one second. Thus, it can be avoided that in the case of a fleeting contact, which due to their short time can actually only be unintentional, an operation takes place or an operating function is triggered.

Furthermore, it can be provided to increase the ease of use and above all the operating safety that the selection of a hotplate is maintained only for a certain time as such, so to speak to give the operator time to change the operating state or give a re-operation command. Such a time period should be in the range of several seconds, for example a maximum of 10 seconds. Thus, incorrect operation can be avoided by too long selection times.

Furthermore, as a safety measure it is possible to monitor, via the control or the actuation sensors, whether the cooking vessel has been moved while the cooking vessel is being touched or when it is touched several times between touching operations. Such a movement of the cooking vessel may mean that the cooking vessel is merely installed or moved, but no operating function is to be triggered. Thus, it is advantageous in this case if no operation is detected or no operating function is triggered.

Furthermore, it can be provided that in the event that two cooking vessels are touched at the same time, so either the touch has taken place at the same time or at least overlaps in time, no service at all. In this case, it is not possible to make a precise distinction as to how the operation was actually intended or which cooking area should actually be selected. In such a case, a signal in the manner of a fault or danger signal can be output to an operator.

Thus, the method according to the invention is characterized in that a cooking vessel is placed on a cooking area or already set up for the operation of a cooking hob described above. If it is touched by an operator within the scope of this, then this is evaluated via the actuation sensor as an actuation of a control element for inputting an operating command of an operating function and the hob responds accordingly.

If a so-called inductive cooking vessel detection sensor used as an actuation sensor and evaluated with Schwingkreisverstimmung, it can be operated at a higher frequency to detect a touch of the cooking vessel. In the aforementioned types of sensors, this frequency, depending on the evaluation method of the frequency measurement, for example, in the range of 2 MHz to 30 MHz, preferably between 8 MHz and 20 MHz. In order to evaluate the extremely small change in the resonant circuit capacity of, for example, about 5 pF by touching the cooking vessel, it is necessary to operate the resonant circuit in the vicinity of the self-resonance of the sensor. From the strainer capacity of the cooker detection sensor, about 50 pF to 200 pF, and a small resonant circuit capacity, about 50 pF to 220 pF, and the cooker detection sensor inductance, about 300 nH to 800 nH, with the cooking vessel installed, a high resonant frequency results.

These and other features will become apparent from the claims but also from the description and the drawings, the individual features each alone or more in the form of sub-combinations in an embodiment of the invention and in other fields be realized and advantageous and protectable Represent embodiments for which protection is claimed here. The subdivision of the application into individual sections as well as intermediate headings does not restrict the general validity of the statements made thereunder.

Brief description of the drawing

Embodiments of the invention are in different variants in the Fig. 1 shown schematically and will be described in more detail below. It shows Fig. 1 a schematic oblique view of a hob according to the invention with four cooking zones and serving as a control device cooking vessel detection and various methods of operation.

Detailed description of the embodiments

In Fig. 1 schematically a hob 11 is shown in an oblique view, in which the invention is implemented in two variants. The hob 11 has a glass ceramic plate 12 which forms the surface. However, this could also consist of other materials. On the glass ceramic plate 12 a plurality of hotplates 14a - d are provided, as in a conventional hob, namely approximately evenly distributed. They can be identified by corresponding markings on the upper side of the glass-ceramic plate 12, for example corresponding prints or the like. Of course, it is also possible to provide so-called switchable multi-circuit cooking, be it in round or oblong shape.

Under each hotplate 14a-d, a heater 16a-d is provided in each case. These are in particular in glass ceramic plates 12 so-called radiant heaters. Alternatively, induction heaters could be used as the type of heater used for the invention is irrelevant in this respect. Each of the heaters 16a-d is controlled by a controller 18 and energized according to a selected cooking or power level. For this purpose, the power switches 20a-d are provided. By means of touch switches 21, which are arranged on the right edge of the glass ceramic plate 12 and have corresponding markings on the top of the plate, the operation of the hob 11 can be done, for example, as setting a cooking or power level for the heater 16 a hob 14. Dazu For example, the touch switches 21 are provided with plus and minus symbols to increase or decrease the power. The touch switches 21 may, for example, be designed as capacitive touch switches and be so-called touch switches. In addition to capacitive operating principles and optical or other can be used, as well as mechanical switches or the like .. By placing a finger 27, the touch switch 21 can be operated according to their function.

Furthermore, below the cooking zones 14, advantageously between glass ceramic plate 12 and heater 16, the so-called cooking vessel detection sensors 22a and d. These can be designed in different forms. In a variant of the invention, a cooking vessel recognition sensor 22a, which has an approximately coil shape and is connected to the controller 18, is provided below the cooking point 14a. Such a sensor is for example in the EP 788 293 A which is expressly referred to in terms of possible implementations.

In another variant of the invention, two cooking vessel detection sensors 22d, which are not formed in coil form, but form two individual surfaces which are arranged at the edge of the cooking area 14d and approximately opposite one another, are arranged below the cooking point 14d. This cooking vessel detection sensors 22d may have a capacitive operating principle, as for example from the DE 42 24 934 A is known. Although they are used there for a different operating principle. However, the purpose is the same, namely the detection of the presence, training and possibly also the size of an attached to the cooking vessel detection sensor cooking vessel placed here with the additional function of detecting the touch of the cooking vessel by an operator 27th

function

In the following, the function will be described with reference to the hotplate 14a with the coil-shaped inductive cooking vessel detection sensor 22a. However, this functional description is expressly not limited to the specific design of the cooking vessel detection sensor 22a, but can be used, either directly or in a corresponding modification, with other cooking vessel detection sensors, especially if they work with electromagnetic fields, so either inductive or capacitive nature ,

Since only the two touch switches 21 are provided in the cooking hob 11 according to the invention for adjusting the power of all the cooking zones 14a-d, the hob must also be able to be switched on. If a cooking vessel 25 is or is being set up at a certain cooking location, then the cooking vessel detection sensor 22 recognizes this together with the controller 18. According to the invention, it is recognized that the cooking vessel 25 is touched with a finger 27, ie a capacitive coupling takes place , As part of In fact, the invention has shown that it is possible to ascertain, with a correspondingly accurate tuning and evaluation of the signals of the cooking vessel detection sensor 22, whether a cooking vessel is being touched. For this purpose, metallic cooking vessels are necessary. By touching the cooking vessel 25 with one or more fingers 27, the capacity of an operator is added, for example, parallel to the resonant circuit capacitance of the sensors. This can be recognized by the signal of the cooking vessel detection sensor 22. In order to detect this contact of the cooking vessel, it is necessary to shift the operating frequency of the cooking vessel detection sensor to the above-mentioned very high values. Alternatively, capacitive leakage currents can also be measured on the finger 27 via similar sensors with capacitive coupling.

If it has been registered via the cooking vessel detection sensor 22 and the controller 18 that the cooking vessel has been touched, this is rated as operation or switching on and the hob is switched on. For this purpose, however, it is necessary to keep the hob or its control always in a kind of stand-by state, since eventually the sensors must be activated or activated in order to quickly and reliably detect such switching on.

As an alternative to touching an already set-up cooking vessel 25a, as shown at the front left, a cooking vessel 25c can also be set up to switch on, as shown on the right by the large movement arrow. The cooking vessel 25c is touched by the hands 28. This corresponds to the detection thus approximately touching an already established cooking vessel.

Likewise, touching a so-called selection, also called selection, take place. This is used to determine at which hotplate 14 in a subsequent process, the cooking or power level is changed. If a cooking vessel 25 is set up, this is recognized by the cooking vessel detection sensor 22 together with the controller 18. The controller 18 evaluates this as a selection of the corresponding hotplate 14. This means that a subsequent actuation of the touch switch 21 for the state of this particular hotplate 14 and the associated heater 16 applies. This is in itself in this way from the prior art in the form of DE 102 11 047 known.

However, in order to make a change in the cooking or power level of a cooking area 14 some time after setting up the cooking vessel or at any time during cooking, especially with multiple cooking zones of the hob 11, this must be selected again. According to the invention, this is done by touching the cooking vessel 25 with a finger 27. It is emphasized that a displacement of the cooking vessel is indeed possible and under certain circumstances, the clarity of a selection can underline. In principle, however, it is not necessary, since such a displacement would have to be so great, at least to the extent that it can be reliably detected by a cooking vessel detection, that under certain circumstances it is considered to be complicated or even impractical.

If it has been registered via the cooking vessel recognition sensor 22 and the controller 18 that the cooking vessel has been touched, this is considered a selection and a subsequent actuation of the touch switches 21 or other state switches then applies exactly to this cooking place. For example, an additional heating zone could also be switched on.

If another cooking vessel 25 is touched after the selection of a hotplate and before actuation of the touch switch 21, the selection of the hotplate advantageously switches to the last actuated or the selection of the cooking surface activated first is canceled.

Above all, it is advantageously provided in the invention that, after the detected contact of a cooking vessel 25, a corresponding signal is output to a user, either optically or acoustically. So, especially when switching on can be signaled. It is not necessary to continue to touch the cooking vessel 25 while changing the state of the hotplate via the touch switches 21. A single touch, possibly with a minimum of time required, may be considered sufficient.

Thus, in one possible embodiment, this means that touching or touching a cooking vessel is recognized by the hob or the actuation sensor and is taken as an actuation corresponding to another actuation via known switches. Thus, either on some input elements or controls such as ON-switch or circuit breaker or the like. be waived. Furthermore, an instinctive operation by touching an erected cooking vessel is possible. Finally, it has been found in the context of investigations of this invention that in many cases, a touch of the cooking vessel, for example, when setting up a cooking vessel with contents to be heated, when lifting the lid or while stirring with simultaneous holding takes place. In practice, these actions are often followed by changes to the switch-on state of the hob or to the power setting of the hotplate.

Claims (15)

1. Electronically controlled hob (11) having a plurality of cooking points (14) on which a cooking vessel (25) can be placed in order to heat up food which is contained in the cooking vessel, wherein a control means (18) and at least one operating sensor (22) for identifying a contact (27, 28) with a cooking vessel on the hob or a cooking point are provided, characterized in that the operating sensor and the control means are designed to identify contact with a cooking vessel (25) on a cooking point by an operator (27, 28) for the purpose of an operator control process on the hob (11) in such a way that the cooking vessel (25) which is placed on a cooking point (14) forms, together with the operating sensor (22), a touch-operated switch for operating the hob by way of an operator control function.
2. Hob according to Claim 1, characterized in that the operating sensor is a capacitively operating operating sensor (22d) or contact sensor, wherein said operating sensor preferably has a sensor area.
3. Hob according to Claim 1, characterized in that the operating sensor is an inductively operating operating sensor (22a) or contact sensor, wherein said operating sensor preferably has a coil.
4. Hob according to one of the preceding claims, characterized in that the operating sensor (22) is simultaneously a cooking vessel detection sensor.
5. Hob according to one of the preceding claims, characterized in that the operating sensor (22) is arranged beneath the hob (11) or beneath a hob plate (12) which is preferably composed of glass ceramic.
6. Hob according to one of the preceding claims, characterized in that a plurality of operating sensors (22d) are provided for each cooking point (14d) in different positions on the cooking point, wherein the plurality of operating sensors can be activated in each case depending on the size of the cooking vessel (25).
7. Hob according to one of the preceding claims, characterized in that the control means (18) is designed to perform some, preferably a large portion, of the operator control functions of the hob (11) by means of the operating sensor (22) by way of contact (27, 28) with the cooking vessel (25).
8. Hob according to one of the preceding claims, characterized in that, by operating the operating sensor (22) by way of contact (27, 28) with a cooking vessel (25) on a cooking point (14), the hob (11) can be set to an operating state such that this operator control function is a switch-on operation.
9. Hob according to one of the preceding claims, characterized in that the control means (18) is designed to distinguish multiple contact (27, 28) with a cooking vessel (25) for operating the operating sensor (22) and to evaluate this as different operations or operator control functions and to convert them into corresponding operator control commands, wherein multiple contact is provided, in particular, for switching on the hob (11).
10. Hob according to one of the preceding claims, characterized in that the control means (18) has a plurality of common operator control elements (21) for changing the operating state of the cooking points (14) depending on the operator or as an operator control function, in particular for setting or changing a power of each individual cooking point, preferably a plus operator control element and a minus operator control element for all cooking points.
11. Method for operating a hob according to one of the preceding claims, characterized in that, by contacting (27, 28) a cooking vessel which is placed on a cooking point (14), this contact is identified and assessed as operation of an operator control element for entering an operator control command as an operator control function.
12. Method according to Claim 11, characterized in that the hob (11) is moved from a deactivated state to an activated state, in particular is switched on, by touching the cooking vessel (25) which is placed on a cooking point (14).
13. Method according to Claim 11 or 12, characterized in that the hob (11) is switched on from the deactivated state only after multiple contact (27, 28) with a cooking vessel (25) which is placed on a cooking point (14), in particular after double contact with the said cooking vessel, wherein, preferably in the case of multiple contact (27, 28) with the cooking vessel (25) as operator control of the hob (11), the operating sensor (22) identifies, by way of the control means (18), whether the cooking vessel has been moved in the process and, when it is established that the cooking vessel has been moved, does not identify operator control and does not convert the contact operations into an operator control command.
14. Method according to one of Claims 11 to 13, characterized in that, after contact with a cooking vessel (25) which is placed on a cooking point (14) as an operator control function, an acknowledgement is output to an operator (27, 28), said acknowledgement preferably being optical and/or acoustic.
15. Method according to one of Claims 11 to 14, characterized in that contact (27, 28) with a cooking vessel (25) which is placed on a cooking point is considered to be an operator control operation only when contact has been made by an operator (27, 28) for a specific time in the range of a few seconds, wherein, preferably in the case of an intended operator control operation by multiple contact, a maximum time period between successive touches must not be exceeded in order to effect an operator control function.

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