DE102015015417A1 - Operating device for a motor vehicle and method for generating a haptic signal - Google Patents

Abstract

The invention relates to an operating device (1) for a motor vehicle, comprising a surface element (2), a base element (3) and at least one intermediate element (4) having a recess (5) and a plurality of electrodes (10, 11, 12). , Furthermore, the invention relates to a method for generating a haptic signal by means of such an operating device (1). In order to provide an operating device (1) for a motor vehicle, by means of which a haptic signal perceptible on a surface (2) can be generated under low space requirements, it is provided according to the invention that on a membrane (6) covering the recess (5) a piezoelectric element (9) is arranged and arranged to bend the membrane (6) upon application of an excitation voltage to at least two of the electrodes (10, 11) and thereby to generate at least one haptic signal on the surface element (2).

Description

The invention relates to an operating device for a motor vehicle according to the preamble of patent claim 1.

From the US 2013/0021087 A1 For example, an input device with a flexible polymer membrane is known in which electrodes are arranged on the polymer membrane. In an operating action, the membrane and thus also the electrodes are deformed, which leads to a surface and resistance change, which is measured by means of a capacitance or resistance measuring circuit. The causative position change of a control element is then determined from the measured values determined. In this case, an electroactive polymer is provided according to an embodiment between two parts of the control element, which can be excited by means of a voltage applied thereto two arranged electrodes voltage to a change in length in the vertical direction of the control element, so that a perceptible by an operator haptic signal can be generated.

From the WO 2010/079151 A1 For example, a device for converting mechanical energy into electrical energy is known which uses at least one piezoelectric transducer. In this case, a shock element is arranged on a deformable element, which can be brought by a deformation of the deformable element in contact with a part of an acoustic resonator. As a result, the at least one piezoelectric transducer is excited to convert the energy transmitted to it via the acoustic resonator into electrical energy. A generation of a haptic signal is not provided.

From the EP 2 323 015 A2 are a provided for a manual operation device and a remote control device, each having a power generation function known. In this case, by means of a piezoelectric element, a force exerted by an operator force is converted into an electrical voltage, which can then be used for signal generation. A generation of a haptic signal is not provided.

Furthermore, such controls are known from the motor vehicle, but there is not given the opportunity to measure the force applied by an operator force and / or a large space is required by the use of an electric motor.

The object of the present invention is to provide an operating device for a motor vehicle, by means of which, in the case of small installation space requirements, an electrically detectable haptic signal can be generated, and to provide a method for generating a haptic signal.

This object is achieved by an operating device with the features of claim 1 and a method having the features of claim 10. Advantageous embodiments of the invention with expedient developments are the subject of the dependent claims.

In order to create an operating device for a motor vehicle, by means of which a haptic signal perceptible on a surface can be generated under low space requirements, it is provided according to the invention that in the case of the operating device mentioned above a piezo element is arranged on a membrane covering the recess and is set up for this purpose to bend the membrane upon application of an excitation voltage to at least two of the electrodes and thereby generate at least one haptic signal on the surface element. In other words, when an excitation voltage is applied to at least two of the electrodes, a deformation of the piezoelectric element takes place, which, since the piezoelement is fixedly arranged on the membrane, transmits to the membrane and therefore also leads to a deformation of the membrane. Thus, this deformation is thus electrically controlled and generated via a direct or indirect connection of the arrangement of the piezoelectric element and the membrane with the surface element on this perceptible by an operator haptic signal.

It is advantageous if the piezoelectric element is arranged so that its change in length takes place substantially parallel to the main extension plane of the membrane.

Such an arrangement has the advantage that a piezoelectric element can be used, which may have a very low height, so that the entire operating device has only small space requirements. As a piezoelectric element can be used a conventional piezoelectric crystal and as a membrane, for example, a thin metal plate, while the necessary excitation voltage can be provided for example via a connection to an electrical system of the motor vehicle.

The recess covered by the membrane also makes it possible to provide a device for measuring a force exerted on the operating device by an operator. In a further embodiment of the invention, a capacitance and / or a capacitance change is measured between two of the electrodes a detection device is provided, wherein one of these two electrodes is formed by the membrane and the second of these two electrodes is formed by an electrode disposed on the opposite side of the membrane electrode and wherein the capacitance in dependence on a perpendicular to a main plane of extension of the membrane adjusts the membrane acting force component. In other words, at least one component of a force exerted by an operator on the operating device leads to a change in distance, in particular to a reduction in distance, between the electrode formed and contacted as an electrode and a second, spaced from the membrane on the opposite side of the recess arranged electrode , This change in distance causes a change in capacitance between the membrane and the opposite electrode, from which the force component acting on the membrane perpendicular to a main extension plane of the membrane can be determined.

An advantage of a so-designed operating device is that with a minimum of required space and required components not only an operating action, but also the force used or even existing during the operating action force curve are detected and additionally targeted by the operator during the Operating action noticeable haptic signal can be generated. By the precise determinability of the force applied at any time, an independent of the speed of the operation independent detection of the operation and, where appropriate, a better detection of an intention of the operator is possible. In order to determine the capacity or the capacitance change and from this the acting force, the membrane and the opposite electrode can be electrically connected, for example, with an evaluation electronics.

In one embodiment of the invention, at least one strain gauge is arranged on the membrane for determining a force component acting on the membrane perpendicular to a main extension plane of the membrane. A force acting perpendicularly on the membrane thus not only leads to a deformation of the membrane itself, but also to a deformation of the strain gage arranged on the membrane and firmly connected to it. By means of an evaluation electronics connected electrically to the strain gauge or strains, the force which has caused the corresponding deformation of the membrane and of the strain gauge (s) can be determined on the basis of the deformation-variable properties of the strain gauge (s).

The use of a strain gauge allows a particularly space-saving, technically easy to implement and cost-effective determination of the force acting perpendicular to the membrane force. The strain gauges or the strain gauges can be glued to the membrane, with a suitable arrangement of several - for example, four - strain gauges allows a particularly advantageous measurement.

In another embodiment of the invention, a device for inductive measurement of a distance of the membrane from a reference element of this device is arranged in the recess of the intermediate element, which is adapted to determine a perpendicular to a main plane of extension of the membrane acting on the membrane force component. In other words, the deformation of the membrane occurring in an acting force in the region of the recess is utilized to determine a distance of the membrane from a stationary within the operating device arranged reference element, from which it is possible to determine the force acting perpendicularly on the membrane.

An inductive distance measurement has a high repeatability, is largely independent of temperature fluctuations and moisture and also not prone to mechanical wear. A device for inductive distance measurement can be realized for example by an inductive proximity switch, which is connected to a corresponding electronics and a power supply - for example, the electrical system of the motor vehicle.

In a further embodiment of the invention, the operating device is adapted to generate a haptic signal when the amount of force component acting perpendicular to a main extension plane of the membrane on the membrane exceeds a predetermined limit. In other words, therefore, a haptic signal can be generated when a force acting perpendicular to the membrane force component is greater or greater than a pre-determined, in particular manufacturer, set value. By setting a suitable limit value, erroneous or unintentional triggering of the haptic signal and a functionality assigned to the operating device can thus be avoided. In addition, an operator can be taught that she has applied sufficient force and thus successfully carried out the intended operator action. Exceeding the specified limit value or the presence of an already greater force from the beginning, for example, by a suitably designed electrical circuit, which may for example comprise a comparator, or by an evaluation electronics connected to the respectively provided device for determining the acting force take place.

In a further embodiment of the invention, one of the electrodes for applying the excitation voltage is arranged directly on the piezoelement between the latter and the surface element. In other words, one of the electrodes for applying the excitation voltage is thus firmly connected to the piezoelectric element on the one side and fixedly connected to the surface element on the other side so that there are no gaps between the surface element, the piezoelement and the electrode arranged between these two elements , This also results in an at least indirect connection of the piezoelectric element with the surface element.

Such an arrangement allows for easy production and a space-saving compact design. By such a layer arrangement of the individual elements, the haptic signal generated by means of the piezoelectric element can be transmitted directly to the surface element, so that it is there as well as possible perceived by an operator. It is particularly advantageous that the amplitude generated by the piezoelectric element is conveyed in full to the user-side surface of the control element.

The connection of the individual components can be produced for example by gluing, bonding or laminating.

In a further embodiment of the invention, the membrane also forms one of the electrodes for applying the excitation voltage. In other words, therefore, the membrane and a further electrode form a pair of electrodes connected to a voltage supply between which a voltage can be generated which serves as an excitation voltage for the piezoelectric element and thus causes a change in the shape or length of the piezoelectric element. The use of the membrane as an electrode is particularly advantageous because in this way an additional electrode, that is an additional component, and thus space, cost and production costs can be saved. A use of the membrane as an electrode can be realized by designing the membrane in a conductive material, such as a metal, wherein a corresponding contact of the membrane is provided.

In a further embodiment of the invention, the recess of the intermediate element is filled with air and / or an elastomer. In other words, the space formed by the recess in the intermediate element can be completely or partially filled with air or completely or partially filled with an elastomer, wherein the optionally provided elastomer must be soft enough to prevent deformation of the membrane into the region of the recess not to hinder the forces typically used by an operator. Advantages of the use of air are the simple, inexpensive, component and manufacturing cost-saving production and the greatest possible avoidance of temperature dependence of the capacitance measurement. By using an elastomer can be advantageously avoided with little effort, a moisture-dependent change in the capacitance between the electrodes.

According to a further embodiment of the invention, a light guide is arranged between the surface element and the piezoelectric element and the surface element is at least partially transparent in the region of the light guide and / or has a recess. The light guide is arranged in particular directly on the surface element and can also extend into optionally provided recesses of the surface element. By a corresponding design of the light guide or of recesses and / or transparent areas of the surface element, the position and / or the associated functionality of the operating device can be made easily recognizable by illumination or lighting effects. Lighting or other lighting effects can be achieved by, for example, lateral coupling of light into the light guide.

In order to provide a method for generating a haptic signal-in particular in response to an operator action-in which an haptic signal perceptible to a surface is electrically controlled by means of an operating device with small space requirements, it is provided according to the invention that when an exciter voltage is applied to at least two electrodes a membrane is curved and thereby the haptic signal is generated on a surface element.

The functional embodiments of the operating device according to the invention described hitherto and in the following as well as in the patent claims are, mutatis mutandis, also transferable to the method according to the invention or to the devices and components used for carrying out the method according to the invention and vice versa.

Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and from the drawings.

Showing:

1 a schematic sectional view of a connected to a device for power supply and signal evaluation operating device for a motor vehicle, according to an embodiment of the present invention,

2 the operating device off 1 in the same schematic sectional view, wherein a force is exerted on the surface element by an indicated operator, so that the piezoelectric element and the electrodes arranged on both sides are deformed, and

3 the operating device off 1 and 2 in the same schematic sectional view, wherein a deformation of these two electrodes, the piezoelectric element and the surface element caused by application of an excitation voltage to the two electrodes arranged on the piezoelectric element in a direction facing away from the base element is shown.

1 shows a schematic sectional view of an operating device 1 for a motor vehicle, with a surface element 2 , an intermediate element arranged thereon 4 with a recess 5 and one on one of the surfel 2 opposite side of the intermediate element 4 arranged base element 3 , The recess 5 thus represents a cavity which through the surface element 2 , the basic element 3 and the intermediate element 4 is limited.

The intermediate element 4 can be formed in two parts, so that it is the recess 5 limited only on two sides or it may be formed in one piece, so that it is the recess 5 on four sides, that is also limited to two opposite, spaced perpendicularly from the plane of the page arranged pages. The intermediate element 4 has at least two opposite and the recess 5 each side facing a gradation between the surface element 2 and the base element 3 on. In the amount of these gradations is a membrane 6 arranged so that it the recess 5 spanned and in bearing areas 7 . 8th the gradations on the intermediate element 4 is fixed. Above the membrane 6 that is on its surface element 2 facing side, and the entire surface with the membrane 6 connected is a piezoelectric element 9 arranged on its the membrane 6 side facing away from the area with the surface element 2 connected is.

In a middle region of the piezoelectric element 9 is between this and the surfel element 2 an electrode 10 arranged, which is also referred to as the first electrode or piezoelectric electrode. The present is the membrane 6 as second or middle electrode 11 educated. On one of the first electrode 10 opposite side of the recess 5 is on the base element 3 a third electrode 12 , which is also referred to as capacitance electrode arranged. The three electrodes 10 . 11 . 12 are via respective contacts 14 with a - shown here for clarity as a single component - device 13 for power supply, evaluation and control electrically connected.

It should be noted that in all figures, the individual components and distances are not necessarily drawn to scale or can fulfill their respective tasks and functionalities in an embodiment with different size ratios and dimensions.

The present invention has in its in 1 illustrated embodiment over known devices on several particularly advantageous properties. With known devices can be performed when using a piezoelectric element as an actuator no real force measurement or no measurement of a sustained force, since a piezoelectric crystal only during a caused by a force mechanical deformation generates a voltage or builds up a charge, but not in a permanently uniform acting Maintains strength. In addition, use of a piezoactuator to generate a haptic signal usually requires a significant height in order to produce a haptic effect that is sufficiently large and sufficient for clear perceptibility by an operator. The combination with an additional device for force measurement usually again requires a much larger space.

To counteract these problems, in the present case is the piezoelectric element 9 on the membrane also serving as an electrode in a dual function 6 arranged, in turn, the recess 5 spans. When an excitation voltage is applied to the first electrode 10 and the membrane 6 , which on both sides of the piezoelectric element 9 are arranged, the piezo element is activated, that is deformed under the influence of between the first electrode 10 and the membrane 6 built-up electric field. The piezo element 9 is designed so that the essential deformation parallel to the main extension planes of the surface element 2 , the membrane 6 and the base element 3 he follows. As a result, a mechanical stress is built up, which is due to the solid and planar connection of the piezoelectric element 9 with the membrane 6 directly on this transmits and to a deformation of the membrane 6 leads. Because the membrane 6 in the bearing regions 7 . 8th at the intermediate element 4 is determined, the mechanical stress leads to a bending of the membrane perpendicular to its main extension plane. As well as the surface element 2 indirectly via the piezoelectric element 9 or the piezoelectric element 9 and the first electrode 10 with the membrane 6 connected, causes the bending of the membrane 6 also to a deformation of the surface element 2 , which in the area of the operating device 1 by an operator in the form of a haptic signal on the surface element 2 is perceptible. The piezo element 9 , the first electrode 10 and the electrode formed as a membrane 6 thus form a piezo actuator for generating a haptic signal.

Because the membrane 6 is formed as an electrode, it can together with the opposite to the base element 3 arranged third electrode 12 as detection means for measuring a capacitance and / or a capacitance change between the membrane 6 and the third electrode 12 be used. Since this capacity is dependent on the distance of the membrane 6 to the third electrode 12 causes a change in distance as in a deformation of the membrane 6 perpendicular to its main extension direction occurs to a capacitance change. From this by means of the device 13 can be measured and evaluated capacity change, the distance change and thus also perpendicular to its main extension plane on the membrane 6 determine acting force. For example, this may be the force exerted by an operator on the surface element 2 in the area of the operating device 1 is exercised. Since a constant-acting force can be detected in this way, the result for an operator is that a successful operation of the operating device 1 regardless of the operating speed and the necessary operating force is always the same.

To the membrane 6 can be used as an electrode, it may for example be formed in the form of a thin metal plate or made of another conductive material. It is important that the size and material thickness of the membrane 6 is designed so that it is sufficiently deformable by a force typically applied by an operator force can be sufficiently deformed, so that in a control action sufficient for a reliable measurement of the resulting capacitance change signal is produced. Corresponding requirements for sufficient deformability also apply to the surface element 2 because this one hand must be sufficiently deformable by an operator to a corresponding deformation of the membrane 6 cause and on the other hand by the from the piezoelectric element 9 , the first electrode 10 and the membrane 6 formed piezoelectric actuator must be sufficiently deformable to one by an operator on the surface element 2 to produce reliably perceptible haptic signal. The surface element 2 can be made for example of a plastic or aluminum in a thickness of, for example, 0.3 mm. It is also conceivable, the surface element only in the range of the operating device 1 To perform with a lower material thickness than in the environment, so that in the operating area ensures sufficient deformability and overall good stability of the entire component is maintained. Will the surface element 2 made of a metallic or conductive material, it is optionally sufficient insulation, in particular with respect to the first electrode 10 provided.

To the membrane 6 reliable and easy to use as an electrode both for the excitation voltage for activation of the piezoelectric element and for capacitance measurement, it is expedient to provide an electrical interconnection, in which the membrane 6 constant at a ground potential.

Alternatively to the illustrated embodiment, it is also conceivable, one or both of the electrodes 10 and 12 in each case to make a multi-part or instead of a respective individual electrode to provide an arrangement of a plurality of electrodes. This can optionally be done to adapt to structural conditions and / or about the electric field built up by the excitation voltage better to the shape of the piezoelectric element 9 adapted and / or an improved capacity measurement are performed.

Overall, with the in 1 illustrated embodiment of the invention, the functionalities of an actuator for generating a haptic signal and a capacity or force measurement for a reliable detection and interpretation of a control action with minimal component complexity realized in a confined space.

2 shows the already in 1 illustrated operating device 1 in the same schematic sectional view, wherein present a state during an operating action, in which by an operator, a force on the operating device 1 exercised is shown. The force exerted by the operator leads to a deformation of the surface element 2 perpendicular to its main plane of extension in the direction of the base element 3 and thus also to a deformation of the directly and / or indirectly in the region of the recess 5 on the surface element 2 arranged components. Specifically, the deformation of the surface element affects 2 on the first electrode 10 , the piezoelectric element 9 and the membrane 6 in the form of respective deformations.

This process reduces the distance of the membrane 6 , which also here as second or middle electrode 11 is formed, to the third electrode 12 , This leads to a through the device 13 Detectable and evaluable capacity change between the membrane 6 and the third electrode 12 , By one of the device 13 detected capacitance change can therefore first on one on the membrane 6 acting force, of course, the sign of the capacitance change is to pay attention to a reduction or increase in the distance between the membrane 6 and the third electrode 12 to interpret correctly. A typical reduction in the distance between the membrane 6 and the third electrode 12 lies in the range up to 100 microns.

When evaluating a measured capacitance change, it may be appropriate to set one or more thresholds. Thus, it can be provided, for example, that a measured change in capacitance is interpreted as intended operator action only when a first threshold value is exceeded, and thus only one of the operating device is subsequently interpreted 1 associated functionality is triggered. This can be light or unintentional touches of the surface element 2 in which only a slight force is applied to the surface element 2 is exercised to be distinguished from a planned and intended operating action, so that it does not lead to an unintentional triggering of the operating device 1 assigned functionality comes.

By setting further threshold values, different functional gradations or different functionalities can optionally be controlled. Alternatively or additionally, it may be provided that, when a defined threshold value of the capacitance change is exceeded or even greater than that required to achieve the corresponding threshold value of the capacitance change, it is necessary to generate a special haptic signal by means of the piezoactuator and thus selectively and optionally to an operator to convey the applied force adapted signal or even a certain sensory perception.

3 also shows the already in 1 and 2 illustrated operating device 1 in the same schematic sectional view, wherein here a state is shown, in which the from the piezoelectric element 9 , the first electrode 10 and the membrane 6 formed piezoelectric actuator by applying an excitation voltage to the first electrode 10 and the electrode formed as a membrane 6 is activated. Specifically, the situation is shown that by the applied excitation voltage bulging of the membrane 6 that is a deformation perpendicular to its main plane of extension in the direction of the surface element 2 and thus of the base element 3 is generated away, which is also indicated by an arrow. By the deformation of the membrane 6 is also at least indirectly a corresponding deformation of the surface element 2 caused by an operator in the form of a haptic signal on the surface element 2 is perceptible. A suitable for this purpose deformation may for example be in a range of 20 microns to 100 microns and z. B. 50 microns.

Regardless of the specific embodiment selected and the representation shown in the figures, further variations of the present invention are conceivable, which will be discussed in the following.

The recess 5 can be completely filled with air, which is particularly advantageous because there are no special demands on the manufacturing process and optionally a seal of the recess 5 be put. In addition, therefore, a substantial temperature independence of the capacitance between the membrane 6 and the third electrode 12 given. However, to unwanted influences of changing humidity in the recess 5 To avoid it may be appropriate to the recess 5 selectively seal and / or in the recess 5 arranged components, in particular the membrane 6 and the third electrode 12 preferably air or moisture-proof with respect to the recess 5 seal. It is conceivable for this purpose, for example, in the recess 5 arranged components to cover at least partially with respective additional membranes or films or envelop. However, it is also conceivable, although associated with a higher cost, in the region of the recess 5 to introduce a sensor for the humidity and to take into account the currently determined values of the humidity in the evaluation of the measured capacity or capacity change.

Alternatively, the problem of unwanted moisture or humidity influences can be avoided by the recess 5 filled with a soft elastomer. Such an elastomer may be both the membrane 6 as well as the third electrode 12 Insulate against unwanted external influences. For the full functionality of the control device 1 To maintain the elastomer must be chosen so that there is a deformation of the membrane 6 no significant resistance.

It may also be a partial filling of the recess 5 be provided with air and / or an elastomer. For example, only in the immediate vicinity of the membrane could 6 and / or the third electrode 12 an elastomer may be provided while the remainder of the recess 5 filled with air.

The determination of the force applied by an operator can not only take place via a capacitance measurement, it is alternatively or additionally also an arrangement of one or more strain gauges on the membrane 6 conceivable. At a deformation of the membrane 6 then deform the strain gauges attached thereto, which leads to a corresponding change in resistance of the strain gauges, which in turn, for example, from the device 13 can be evaluated to this way on the operating device 1 determine acting force. Several appropriately arranged strain gauges offer advantages over a single strain gauge in terms of precision and / or the speed of a corresponding measurement. When using four strain gauges, for example, the principle of a Wheatstone bridge can be used.

Another alternative for determining a on the operating device 1 acting force consists in an inductive measurement of the distance of the membrane 6 from a reference element. Such an inductive distance measurement can be realized for example by means of an inductive proximity switch whose essential components, for example, instead of the third electrode 12 on the base element 3 in the recess 5 be arranged and as a reference element for the determination of the distance to the membrane 6 can serve. Also in this case, a corresponding power supply through the electrical system of the motor vehicle and an evaluation and control by the device 13 and a corresponding connection via a contact 14 respectively.

In order to provide a further dimension or a further channel for signals or for an information transmission to an operator in addition to the haptic component, can be used as part of the operating device 1 a light guide can be provided. Such a light guide can in particular in the region of the piezo actuator or in the haptically active region of the operating device 1 provided and there, for example, directly to the base element 3 facing side of the surface element 2 be arranged. In order to make perceived in a light guide such coupled light for an operator, the surface element 2 in particular in the region of the light guide, for example, be made transparent or semitransparent or be provided with correspondingly shaped recesses. A semi-transparent design can be achieved for example by a suitably designed PVD or lacquer coating, while optionally in the surface element 2 provided recesses can be filled either by the material of the light guide itself or by another transparent or semitransparent material.

The light guide or corresponding recesses or transparent or semitransparent areas of the surface element 2 For example, according to one of the operating device 1 be designed assigned functionality, so that for example via a respective on or off lighting a corresponding on or off state of the corresponding functionality in a simple and intuitive way an operator can be taught. Furthermore, it is conceivable to signal or convey additional information or further feedback during an operating process, for example via the intensity or color of a lighting.

In a method for generating a haptic signal by means of an operating device of the type described above, upon application of an excitation voltage to at least two of the electrodes - here, for example, to the electrodes 10 . 11 - A deformation or change in length of the piezoelectric element 9 caused and thereby the membrane 6 curved. This creates the haptic signal on the surface element 2 ,

By a targeted and appropriately adjusted control of the excitation voltage, the induced deformation can be controlled, so that different and also perceived by an operator differently perceived haptic signals can be generated. This can be targeted to convey different information and feedback to an operator. Thus, in addition to a single haptic pulse, an optionally permanently maintained vibration can also be generated, thus enabling an operator, for example, to adjust the position of the operating device 1 exclusively using the sense of touch, that is to say in particular without averting the view from the traffic situation.

A preferred control of the haptic signal is to generate a targeted haptic signal when exceeding a specified threshold of capacitance change, which gives an impression to the operator or the Perception senses having operated a conventional mechanical switch or button.

For such a method can also all previously described developments and variants of the operating device 1 including the facility 13 be used for power supply, evaluation and control.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2013/0021087 A1 [0002]
• WO 2010/079151 A1 [0003]
• EP 2323015 A2 [0004]

Claims (10)

Operating device ( 1 ) for a motor vehicle, having a surface element ( 2 ), a base element ( 3 ) and at least one interposed therebetween, a recess ( 5 ) intermediate element ( 4 ) as well as several electrodes ( 10 . 11 . 12 ), characterized in that on one the recess ( 5 ) covering membrane ( 6 ) a piezo element ( 9 ) is arranged and adapted to apply upon application of an excitation voltage to at least two of the electrodes ( 10 . 11 ) the membrane ( 6 ) and thereby at least one haptic signal on the surface element ( 2 ) to create. Operating device ( 1 ) according to claim 1, characterized in that a detection device is provided for measuring a capacitance and / or a capacitance change between two of the electrodes ( 11 . 12 ), one of these two electrodes ( 11 ) through the membrane ( 6 ) and the second of these two electrodes ( 12 ) through one on one of the membrane ( 6 ) opposite side of the recess ( 5 ) arranged electrode ( 12 ) and wherein the capacitance is dependent on a plane perpendicular to a main plane of extension of the membrane ( 6 ) on the membrane ( 6 ) adjusts the force component. Operating device ( 1 ) according to one of the preceding claims, characterized in that on the membrane ( 6 ) at least one strain gauge for determining a perpendicular to a main plane of extension of the membrane ( 6 ) on the membrane ( 6 ) acting force component is arranged. Operating device ( 1 ) according to one of claims 1 or 2, characterized in that in the recess ( 5 ) means for inductive distance measurement of a distance of the membrane ( 6 ) is arranged by a reference element of this device, which is adapted to a perpendicular to a main plane of extension of the membrane ( 6 ) on the membrane ( 6 ) to determine acting force component. Operating device ( 1 ) according to one of claims 2 to 4, characterized in that the operating device ( 1 ) is adapted to generate a haptic signal when the amount of perpendicular to a main plane of extension of the membrane ( 6 ) on the membrane ( 6 ) force component exceeds a predetermined limit. Operating device according to one of the preceding claims, characterized in that one of the electrodes ( 10 ) for applying the excitation voltage directly to the piezoelectric element ( 9 ) between this and the surface element ( 2 ) is arranged. Operating device ( 1 ) according to one of the preceding claims, characterized in that the membrane ( 6 ) one of the electrodes ( 11 ) for applying the excitation voltage forms. Operating device ( 1 ) according to one of claims 1 to 7, characterized in that the recess ( 5 ) of the intermediate element ( 4 ) is filled with air and / or an elastomer. Operating device ( 1 ) according to one of the preceding claims, characterized in that between the surface element ( 2 ) and the piezo element ( 9 ) arranged a light guide and the surface element ( 2 ) is at least partially translucent in the region of the optical waveguide and / or has at least one recess. Method for generating a haptic signal, characterized in that by means of an operating device ( 1 ) according to one of the preceding claims when applying an excitation voltage to at least two of the electrodes ( 10 . 11 ) the membrane ( 6 ) and thereby the haptic signal on the surface element ( 2 ) is produced.

Images