WO2022101417A1

WO2022101417A1 - Electrode configuration for a capacitive switch arrangement

Info

Publication number: WO2022101417A1
Application number: PCT/EP2021/081540
Authority: WO
Inventors: Michael Messner; Claus-Michael WEH; Tobias LEIBER
Original assignee: Marquardt Gmbh
Priority date: 2020-11-13
Filing date: 2021-11-12
Publication date: 2022-05-19
Also published as: DE102020214333A1

Abstract

The invention relates to an electrode configuration for a capacitive switch arrangement, having at least two touch electrodes (3, 13, 24) and at least two counter electrodes (4, 14), the at least two touch electrodes (3, 13, 24) and the at least two counter electrodes (4, 14) each being arranged in series such that each of the at least two touch electrodes (3, 13, 24) can be brought into capacitive coupling with a respective one of the at least two counter electrodes (4, 14), and a distance between two touch electrodes (3, 13, 24) arranged directly in succession being selected such that a high resolution capacity is achieved and at the same time an influence on one touch electrode (3, 13, 24) from other touch electrodes (3, 13, 24) is reduced.

Description

Electrode configuration for a capacitive switch array

The present invention relates to an electrode configuration for a capacitive switch arrangement and a capacitive switch arrangement which has such an electrode configuration with which a reliable electrical connection can be implemented in a simple manner even with complex touch surfaces.

Operating devices for manually setting and/or changing the operating parameters of the device exist for a wide variety of electrical devices. Proximity switches, such as capacitive switches, have been adopted for use on vehicles, for example, to operate devices such as interior maps or overhead lights, sunroofs, and various other devices.

Capacitive switches typically employ one or more capacitive sensors to generate a sensing activation field and to detect changes in the activation field indicative of a user actuation of the switch or an actuator of the switch, typically caused by a User's finger in close proximity to or in contact with the sensor. In this case, capacitive switches are generally designed to detect user actuations based on a comparison of a detected activation field with a threshold. In particular, such capacitive switches usually have electrodes laid out with circuitry formed on a substrate.

However, the electrically conductive connection of complex devices or complex touch surfaces is often difficult, especially with isolated, transparent touch electrodes, for example due to surface protection, design, coatings, etc. It is important to be able to achieve the highest possible resolution furthermore, it is often also desirable to accommodate a large number of such touch electrodes in a limited area. However, it also proves to be problematic in this connection that errors occur in the signal transmission, for example crosstalk can if a plurality of touch electrodes are arranged within a limited area.

Document WO 2013/041520 A1 discloses an operating device, in particular for a vehicle component, which has a front wall with one or more fixed symbol fields on the front and a rear side with a capacitive proximity sensor system that has individual electrodes assigned to the symbol fields, wel - surface are arranged on the back of the front wall, and the back of the front wall facing the support plate, which is arranged at a distance from the front wall, has, wherein the capacitive proximity sensor for identifying that symbol field, which is an object, in particular a hand or the Finger of a hand approaches, having an evaluation unit connected to the electrodes. Electrode carrier elements assigned to the individual symbol fields are arranged between the front wall and the carrier plate electrically connected contact field of the carrier plate is electrically contacted, the electrode end of each electrode carrier element having a protruding contact edge which extends at least partially around a symbol field assigned to the electrode carrier element and bears against the back of the front wall, the electrode running along the contact edge of the electrode denträgerelements is formed without being electrically connected to the front wall, and each electrode carrier element has an electrically conductive area for the electrical connection of its electrode with its contact end and thus the Has contact field of the support plate.

From the publication DE 11 2007 001 643 T5, a touch-sensitive user interface is known, which has a plurality of measuring surfaces, a measurement circuit that is coupled to the measuring surfaces and capable of generating output signals, the couplings between a pointing object and corresponding ones of the measurement areas, and a controller capable of receiving the output signals of the measurement circuit, determining from the output signals a combination of the measurement areas which are activated by the presence of the pointing object, to compare the combination of activated measuring areas with at least one predefined combination of the measuring areas, and a selected one of the measuring areas according to an agreement determining mood between the combination of activated sensing areas and one of the at least one predefined combination of sensing areas includes.

An electrode configuration for a capacitive sensor device is known from the publication DE 10 2011 003 734 B3, which comprises a transmitting electrode and a receiving electrode, wherein the transmitting electrode can be brought into a capacitive coupling with the receiving electrode, wherein the electrode configuration has at least one first sensor area and at least forms a second sensor area, the electrode areas of the transmitting electrode and the receiving electrode in the first sensor area being small in comparison to the electrode areas of the transmitting electrode and the receiving electrode in the second sensor area.

From the document DE 10 2014 212 250 A1 a device with a capacitive sensor containing electrodes and a control unit is known, wherein the control unit contains a processing unit and a memory, wherein when a logic is executed by the processing unit, the logic being able to select a first subset of electrodes for a measurement and to select one of the electrodes from a second subset of the electrodes as a reference drive electrode, the logic being further able to calculate a difference between a capacitance measurement the first subset and a capacitance measurement of the reference drive electrode, and wherein the logic is also operable to adjust the capacitance measurement of the first electrode based at least in part on the difference.

The object of embodiments of the invention is to specify an electrode configuration for a capacitive switch arrangement and a capacitive switch arrangement which has such an electrode configuration, with which a reliable electrically conductive connection can be implemented in a simple manner even with complex touch surfaces.

This problem is solved by the subject matter of the independent claims. Further advantageous developments are the subject matter of the dependent claims.

According to one embodiment of the invention, this object is achieved by an electrode configuration for a capacitive switch arrangement which has at least two touch electrodes and at least two counter-electrodes, the touch electrodes and the Counter-electrodes are each arranged in a row in such a way that each of the at least two touch electrodes can be capacitively coupled to one of the at least two counter-electrodes, and wherein a distance between two touch electrodes arranged directly one after the other is selected in each case such that a high resolving power is achieved and at the same time the influence of one touch electrode by other touch electrodes is reduced.

The influencing of a touch or transmission electrode by other touch or transmission electrodes is understood here as interference or falsification of a signal supplied by one of the touch electrodes by other touch electrodes. Such a disturbance or falsification can be caused, for example, by parasitic capacitances or crosstalk. Parasitic capacitance is understood to mean an unwanted and usually disruptive electrical capacitance that exists, for example, between two supply lines or two touch electrodes arranged one after the other, with the actual value of the parasitic capacitance being based, among other things, on the distance between the two directly one after the other arranged touch electrodes. Crosstalk is also commonly referred to as electrical noise or signal interference between conductors. Electrical noise causes several undesired effects. First, electrical noise can reduce the amplitude of a signal upon actuation of an actuator of a capacitive switch assembly, thereby reducing the accuracy of estimating an actuation location at which the actuator was actuated, and thereby reducing the accuracy of estimating a selected function. Furthermore, the signals, for example the amplitude of a detected signal, can be corrupted, which in turn reduces the accuracy of the evaluation of the actuation. The crosstalk therefore leads to undesired signals in the transfer function, which impair the signals and their evaluation.

With such an electrode configuration, a distance between touch electrodes arranged directly one after the other is selected in such a way that the influencing of signals supplied by one touch electrode by other touch electrodes and thus also the subsequent evaluation of signals in an evaluation unit are reduced as far as possible. The fact that a distance between directly consecutive touch electrodes is also selected in such a way that a high level of resolution is achieved nevertheless also ensures that a difference between two slightly different actuation locations is also reliably detected can be reliably differentiated, for example, between actuations at a first actuation location and actuations at a second actuation location that is slightly spaced apart from the first actuation location. Overall, an electrode configuration for a capacitive switch arrangement is thus specified, with which errors in the signal transmission can be avoided, in particular even in the case of complex touch surfaces, and the subsequent evaluation of the signals can be further optimized.

The distance between two touch electrodes arranged directly one after the other can be greater than or equal to 1 mm. Thus, by selecting a minimum distance of 1 mm between individual, directly consecutive touch electrodes, disruptive parasitic capacitances and crosstalk in such capacitive switch arrangements can usually be effectively avoided.

In particular, the distance between two touch electrodes arranged directly one after the other can be selected in such a way that the number of touch electrodes arranged in a predetermined area is maximized, with the boundary condition that at the same time the influence of one touch electrode by other touch electrodes is reduced. Because the number of touch electrodes arranged in a predetermined, ie known or determinable area is maximized, the number of actuation locations and associated functions provided in this predetermined area can also be maximized at the same time and thus the resolution capacity can also be maximized will. Due to the boundary condition on which this maximization is based, that the influence of a touch electrode by other touch electrodes is reduced, it can be ensured at the same time that the influence of signals supplied by a touch electrode by other touch electrodes and thus also the subsequent evaluation of signals in an evaluation unit is reduced as far as possible will.

Furthermore, a distance between a touch electrode and a counter or receiving electrode that can be brought into a capacitive coupling with this touch electrode can be selected in each case in such a way that a coupling quality between a touch electrode and the counter electrode that can be brought into a capacitive coupling with this touch electrode is high in each case. The coupling quality or the coupling factor is dependent on the distance between the touch electrode and the respective counter-electrode. For example, is the touch electrode too close to the one with this touch electrode in a counter-electrode that can be capacitively coupled, the system works in an over-coupled area in which, for example, resonance frequencies split. However, if the touch electrode is located too far away from the counter-electrode that can be brought into a capacitive coupling with this touch electrode, the resulting field strength is too low to still ensure adequate signal transmission. The fact that the coupling quality is high means that the touch electrode and the corresponding counter-electrode are spaced apart from one another in such a way that signal transmission between the touch electrode and the corresponding counter-electrode is as optimal as possible and potential signal attenuation can be kept small. The fact that the distance between a touch electrode and a counter-electrode that can be brought into a capacitive coupling with this is selected in each case such that a coupling quality between a touch electrode and a counter-electrode that can be brought into a capacitive coupling with this touch electrode is high in each case Errors in signal transmission can be avoided even better and the subsequent evaluation of the signals can be further optimized.

The distance between a touch electrode and a counter-electrode that can be brought into a capacitive coupling with this touch electrode can be greater than or equal to 0.1 mm and less than or equal to 0.3 mm. With such capacitive switch arrangements, signal attenuation of the serial coupling quality can be kept small and usually at a distance between a touch electrode and the counter-electrode that can be capacitively coupled to this touch electrode, which is between 0.1 mm and 0.3 mm a high coupling quality can be guaranteed.

Furthermore, the electrodes and in particular the at least two touch electrodes can each be transparent electrodes. Transparent electrodes have the advantage that they can be used over a display in order to provide a touch-sensitive screen that displays information to a user or operator, for example in the form of a selection menu, and through touching certain areas of the display the user can react. However, compared to the materials usually used for non-transparent electrodes, or to non-transparent electrodes based on these materials, such transparent electrodes usually have a lower electrical conductivity, so that it is particularly important to keep the distance between the to optimize individual transparent electrodes and in particular the distance between individual transparent touch electrodes, in particular to keep it as small as possible in order to achieve the highest possible resolution to achieve. The corresponding transparent electrode materials can be, for example, films with an indium tin oxide coating (IOT) or films based on polyethylene terephthalate (PET). In particular, however, the material of the transparent electrodes should be selected in such a way that the conductivity of all the electrodes is as high as possible, while at the same time the insulation between individual electrodes should have as high a resistance as possible.

With a further embodiment of the invention, a capacitive switch arrangement is also specified, the capacitive switch arrangement having an electrode configuration as described above, an actuator and a flexible printed circuit board, the touch electrodes being mounted on the actuator and the counter electrodes on the flexible circuit board are attached.

Such a capacitive circuit arrangement has the advantage that it has an electrode configuration with which an electrically conductive connection can be implemented in a simple manner even with complex touch surfaces, especially since the electrical connection and signal transmission is implemented by a plate capacitor Plates is formed by the touch and the corresponding counter electrodes. Furthermore, errors in the signal transmission can also be avoided and the subsequent evaluation of the signals can be further optimized. A distance between touch or transmission electrodes arranged directly one after the other is selected in such a way that the influence of signals supplied by one touch electrode by other touch electrodes and thus also the subsequent evaluation of signals in an evaluation unit are reduced as far as possible. The fact that a distance between directly consecutive touch electrodes is also selected in such a way that a high resolution is achieved nevertheless also ensures that a difference between two slightly different actuation locations can be reliably detected, for example reliably a distinction can be made between actuation of an actuating element at a first actuation location and actuation of the actuating element at a second actuation location, which is slightly spaced apart from the first actuation location.

In this case, the flexible printed circuit board can be connected to the actuating element by means of an adhesive connection. The fact that the flexible circuit board can be glued to the actuator has the advantage that even with a complex arrangement of touch surfaces, a electrically conductive connection and a reliable signal transmission can be realized without great effort, without the complex and expensive conversions would be necessary with this touch electrode in a capacitive coupling can be brought into a counter-electrode is high. The fact that the coupling quality is high means in turn that the touch electrode and the corresponding counter-electrode are spaced apart from one another in such a way that signal transmission between the touch electrode and the corresponding counter-electrode is as optimal as possible and potential signal attenuations can be kept small.

A further embodiment of the invention also specifies a device which has a capacitive switch arrangement as described above and an evaluation unit coupled to the counter-electrodes for detecting an actuation of the capacitive switch arrangement.

Such a device has the advantage that it has an electrode configuration with which an electrically conductive connection can be implemented in a simple manner even with complex touch surfaces, especially since the electrical connection and signal transmission is implemented by a plate capacitor whose plates are connected by the touch and the corresponding counter electrodes are formed. Errors in the signal transmission can also be avoided and the subsequent evaluation of the signals can be further optimized. A distance between touch electrodes arranged directly one after the other is selected such that the influence of signals supplied by one touch electrode by other touch electrodes and thus also the subsequent evaluation of signals in the evaluation unit are reduced as far as possible. The fact that a distance between directly consecutive touch electrodes is also selected in such a way that a high resolution is achieved nevertheless also ensures that a difference between two slightly different actuation locations of the capacitive switch arrangement can be reliably detected For example, a reliable distinction can be made between actuations at a first actuation location and actuations at a second actuation location that is slightly spaced apart from the first actuation location.

In summary, it can be stated that with the present invention, an electrode configuration for a capacitive switch arrangement and a capacitive switch arrangement, which has such an electrode configuration, with which a reliable electrically conductive connection can be implemented in a simple manner even with complex touch surfaces.

In particular, an electrode configuration is specified in which a distance between touch electrodes arranged directly one after the other is selected in such a way that the influence of signals supplied by one touch electrode by other touch electrodes and thus also the subsequent evaluation of signals in an evaluation unit are reduced as far as possible. The fact that a distance between directly consecutive touch electrodes is also selected in such a way that a high resolution is achieved, nevertheless also ensures that a difference between two slightly different measurement signals can be reliably detected, for example reliably a distinction can be made between actuations of an actuating element of the capacitive switch arrangement at a first actuation location and actuations of the actuating element at a second actuation location at a slight distance from the first actuation location. Overall, an electrode configuration for a capacitive circuit arrangement is thus specified with which errors in the signal transmission can be avoided even with complex touch surfaces and the subsequent evaluation of the signals can be further optimized.

Furthermore, because a flexible printed circuit board having the counter electrodes is connected to the actuating element of the capacitive switch arrangement by an adhesive connection, i.e. the flexible printed circuit board is glued to the actuating element, a reliable electrically conductive connection can be achieved in a simple manner even with complex touch surfaces - binding and signal transmission can be realized.

The invention will now be explained in more detail with reference to the accompanying figures.

FIG. 1 shows a view of a device according to embodiments of the invention;

FIG. 2 shows a view of an electrode configuration for a capacitive switch arrangement according to embodiments of the invention; FIG. 3A shows a schematic perspective plan view of a top side of an actuating element of a capacitive switch arrangement according to a first embodiment;

FIG. 3B shows a schematic perspective plan view of an underside of an actuating element of the capacitive switch arrangement according to the first embodiment;

FIG. 4 shows a cross-sectional view of a capacitive switch arrangement according to embodiments of the invention.

FIG. 1 shows a view of a device 1 according to embodiments of the invention.

As FIG. 1 shows, the device has a capacitive switch arrangement 2 .

However, the electrically conductive connection of complex devices or complex touch surfaces is often difficult, especially with isolated, transparent touch electrodes, for example due to surface protection, design, coatings, etc. It is important to be able to achieve the highest possible resolution white It is also often desirable to accommodate a large number of such touch electrodes in a limited area. However, it also proves to be problematic here that errors in the signal transmission, for example crosstalk, can occur if a large number of touch electrodes are arranged within a limited area.

According to the embodiments of Figure 1, the capacitive switch arrangement 2 has touch electrodes 3 and counter-electrodes 4, each of the touch electrodes 3 being capacitively coupled to one of the counter-electrodes 4, and the device 1 having another one with the counter-electrodes 4 coupled evaluation unit 5, wherein the evaluation unit 5 is designed to detect an actuation of the capacitive switch arrangement 2. In particular, the evaluation unit 5 is designed to determine an actuation location at which the capacitive switch arrangement is actuated, and thus also a selected function, from detected signals and in particular from signals tapped off at the counter-electrodes 4 .

The device according to FIG. 1 is based on a principle in which a transmitting electrode 3 is supplied with an electrical alternating signal that is provided by a signal generator 6 . According to the embodiments of FIG. 1, the evaluation unit 5 and the signal generator are integrated into a common control unit 7. Furthermore, the evaluation unit and the signal generator can also be designed separately from one another.

Due to the alternating electrical signal, an alternating electrical field is emitted at the touch electrode 3 . When an object approaches the touch electrode 3, the alternating electric field emitted at the touch electrode 3 is coupled into the counter-electrode via the object, so that a capacitive path is formed between a transmitter and a receiver, in particular between the signal generator 6 and the evaluation unit 5. When the capacitive switch arrangement 2 is actuated, an electrical signal tapped off at the counter-electrode 4 changes, with the change in the tapped electrical signal being indicative of the actuation of the capacitive switch arrangement 2 . This method is also usually referred to as a transmission method. The two sensor electrodes 3, 4 form what is known as a sensor zone, which is symbolized in FIG However, the electrically conductive connection of complex devices or complex touch surfaces is often difficult, especially with isolated, transparent touch electrodes, for example due to surface protection, design, coatings, etc. It is important to be able to achieve the highest possible resolution furthermore, it is often also desirable to accommodate a large number of such touch electrodes 3 in a limited area. However, it also proves to be problematic here that errors in the signal transmission, for example crosstalk, can occur if a large number of touch electrodes are arranged within a limited area.

According to the embodiments in FIG. 1, the touch electrodes 3 and the counter electrodes 4 are combined in an electrode configuration 9, with the touch electrodes 3 and the counter electrodes 4 being arranged in a row in such a way that each of the touch electrodes 3 is equipped with a counter electrode 4, as described above, can be brought into a capacitive coupling. In this case, a distance between two touch electrodes 3 arranged directly one after the other is further selected in such a way that a high resolution capacity is achieved and at the same time the influence of one touch electrode 3 by other touch electrodes 3 is reduced. The distance between touch electrodes 3 arranged directly one after the other is symbolized in FIG. 1 by the arrow provided with the reference symbol dss.

The influencing of a touch electrode 3 by other touch electrodes 3 is understood here as interference or falsification of a signal supplied by one of the touch electrodes 3 by other touch electrodes 3 . Such a disturbance or falsification can be caused, for example, by parasitic capacitances or crosstalk. Parasitic capacitance is understood to mean an unwanted and usually disruptive electrical capacitance that exists, for example, between two supply lines or two touch electrodes 3 arranged directly one after the other, with the actual value of the parasitic capacitance being directly dependent on the distance between the two, among other things consecutively arranged touch electrodes 3 based. Crosstalk is also commonly referred to as electrical noise or signal interference between conductors. Electrical noise causes several undesirable effects. First, electrical noise can reduce the amplitude of a signal when the object approaches the capacitive switch assembly 2 and/or when the capacitive switch assembly 2 is actuated, thereby reducing the accuracy of the estimation of an actuation location at which a Actuator of the capacitive switch arrangement 2 is actuated is reduced. Furthermore, the signals, for example the amplitude of a detected signal, can be falsified, which in turn reduces the accuracy of the evaluation and in particular the estimation of the actuation location. The crosstalk therefore leads to unwanted signals in the transfer function, which degrade the signals and their evaluation.

In the case of the electrode configuration 9 according to the embodiments in Figure 1, a distance between touch electrodes 3 arranged directly one after the other is selected in such a way that influencing of signals supplied by one touch electrode 3 by other touch electrodes 3 and thus also the subsequent evaluation of signals in the evaluation unit 5 be reduced as far as possible. The fact that a distance between directly consecutive touch electrodes 3 is also selected in such a way that a high resolution is achieved, nevertheless also ensures that a difference between two slightly different actuation locations can be reliably detected, for example reliably between Actuations of the capacitive switch arrangement 2 at a first actuation location and actuations of the capacitive switch arrangement at a second actuation location that is slightly spaced apart from the first actuation location can be distinguished. Overall, the capacitive switch arrangement 2 thus has an electrode configuration 9 with which errors in the signal transmission can be avoided even with complex touch surfaces and the subsequent evaluation of the signals can be further optimized.

According to the embodiments of FIG. 1, a distance between touch electrodes 3 arranged directly one after the other is always the same. Furthermore, the distance between individual touch electrodes arranged directly one after the other can also vary and thus be of different sizes.

According to the embodiments in FIG. 1, the touch electrodes 3 and the counter-electrodes are also each transparent electrodes 10. Due to the lower electrical conductivity compared to materials for non-transparent electrodes or to non-transparent electrodes based on these materials , it is important to optimize the distance between the individual transparent electrodes and in particular the distance between the individual transparent touch electrodes, in particular to keep it as small as possible in order to achieve the highest possible resolution. The electrodes can each be made of a transparent and conductive material such as indi- tin oxide (IOT), the conductive material! completely covers the surface of the shape of the electrodes. That the conductive material! however, the area of the shape of each electrode completely covered is just an example. Rather, in certain embodiments, the conductive material may cover much less than the full area of the shape of the individual electrodes. In addition, the transparent, conductive material can also be any other transparent and electrically conductive material. In particular, however, the material of the transparent electrodes should be selected in such a way that the conductivity of all the electrodes is as high as possible, while at the same time the insulation between the individual electrodes should have as high a resistance as possible.

FIG. 2 shows an electrode configuration 11 for a capacitive switch arrangement according to embodiments of the invention.

As FIG. 2 shows, the electrode configuration 11 has at least two touch electrodes 13 and at least two counter-electrodes 14, with two touch electrodes in each case in FIG

13 and two counter electrodes 14 are shown.

As can also be seen, the touch electrodes 13 and the counter-electrodes 14 are each arranged in a row, with the touch electrodes 13 and the counter-electrodes

14 are each arranged in a row in such a way that each of the touch electrodes 13 can be brought into a capacitive coupling with one of the counter electrodes 14, wherein a distance between two touch electrodes 13 arranged directly one after the other is in turn selected such that a high resolving power is achieved and at the same time the influence of a touch electrode 13 by other touch electrodes 13 is reduced. A distance between touch electrodes 13 arranged directly one after the other is again symbolized in FIG. 2 by the arrow provided with the reference symbol _dss . In particular, the electrode configuration 11 consists of a sequence of touch electrodes 13 arranged one behind the other in a row and a sequence of counter electrodes 14 arranged one behind the other in a row, with a distance between directly adjacent touch electrodes 13 being selected in such a way that a high resolution is achieved and at the same time an influence on a touch electrode 13 by other touch electrodes 13 is reduced.

When one touch electrode 13 is influenced by other touch electrodes 13, this in turn causes a disruption or falsification of one of the touch electrodes 13 signal supplied by other touch electrodes 13 understood. Such a disturbance or falsification can be caused, for example, by parasitic capacitances or crosstalk. Parasitic capacitance is understood to mean an unwanted and usually disruptive electrical capacitance that exists, for example, between two supply lines or two touch electrodes 13 arranged one after the other, with the actual value of the parasitic capacitance being based, among other things, on the distance between the two touch electrodes 13 arranged directly one after the other based. Electrical noise or signal interference between conductors is also generally referred to as crosstalk. Electrical noise causes several undesirable effects. First, electrical noise can reduce the amplitude of a signal upon actuation of a capacitive switch assembly, thereby reducing the accuracy of estimating an actuation location at which an actuator of the capacitive switch assembly is actuated. Furthermore, the signals, for example the amplitude of a detected signal, can be corrupted, which in turn reduces the accuracy of the evaluation. The crosstalk therefore leads to undesired signals in the transfer function, which degrade the signals and their evaluation.

According to the embodiments of FIG. 2, the distance d _ss between two touch electrodes 13 arranged directly one after the other is in each case greater than or equal to 1 mm. Thus, by selecting a minimum distance of 1 mm between individual, directly consecutive touch electrodes, disruptive parasitic capacitances and crosstalk in such capacitive switch arrangements can usually be effectively avoided.

According to the embodiments in Figure 2, a distance d _ss between two touch electrodes 13 arranged directly one after the other is also selected in each case in such a way that the number of touch electrodes 13 arranged in a predetermined area is maximized, under the boundary condition that one touch electrode is influenced at the same time 13 is reduced by other touch electrodes 13.

As Figure 2 also shows, a distance between a touch electrode 13 and a counter-electrode 14 that can be brought into a capacitive coupling with this touch electrode 13 is further selected in each case in such a way that a coupling quality between a touch electrode 13 and the counter-electrode that can be brought into a capacitive coupling with this touch electrode 13 14 each is high. The coupling quality or the coupling factor depends on the Distance between the touch electrode 13 and the respective counter-electrode 14. If the touch electrode is, for example, too close to the counter-electrode that can be capacitively coupled with this touch electrode, the system works in an over-coupled range in which, for example, resonance frequencies split. However, if the touch electrode is too far away from the counter-electrode that can be capacitively coupled to this touch electrode, the resulting field strength is too low to still ensure adequate signal transmission. The fact that the coupling quality is high means that the touch electrode 13 and the corresponding counter-electrode 14 are spaced apart from one another in such a way that signal transmission between the touch electrode 13 and the corresponding counter-electrode 14 is as optimal as possible and potential signal attenuation can be kept small. Furthermore, the distance between a touch electrode 13 and a counter-electrode 14 that can be brought into a capacitive coupling with this touch electrode 13 is symbolized in FIG. 2 by the arrow provided with the reference symbol d _SE .

According to the embodiments of FIG. 2, a distance between a touch electrode 13 and a counter-electrode 14 that can be capacitively coupled thereto is always the same. Furthermore, the distance between individual touch electrodes and corresponding counter-electrodes that can be brought into a capacitive coupling with these can also vary and thus be of different sizes.

According to the embodiments in FIG. 2, the distance d _SE between a touch electrode 13 and a counter-electrode 14 that can be brought into a capacitive coupling with this touch electrode 13 is in particular greater than or equal to 0.1 mm and less than or equal to 0.3 mm . In such capacitive switch arrangements, signal attenuation of the serial coupling quality can be kept small and a high coupling quality can be guaranteed.

In this case, the touch electrodes 13 are arranged on a surface 12 of an actuating member 16 and the counter-electrodes 14 are arranged on a flexible printed circuit board 10 .

The flexible printed circuit board 10 has on one surface 15 an adhesive material, not shown in FIG. 2, by means of which the flexible printed circuit board is bonded to the actuating element can be. For example, the flexible printed circuit board can be glued to the actuator using a double-sided adhesive film. In this case, for example, a double-sided adhesive film can be used in the manner of a double-sided adhesive tape. The double-sided adhesive film is of particular advantage since it can be pre-cut to a predefined size before application to the flexible circuit board and/or the actuator. There are also advantages when storing the double-sided adhesive film, since it can be supplied in rolls.

Figures 3A and 3B show the application of such an electrode configuration 20 to a correspondingly complex actuating member 21.

In particular, FIG. 3A shows a schematic perspective plan view of an upper side 22 of an actuating member 21 according to a first embodiment.

The actuator is in particular a monolith, for example a monolith made of aluminum.

In order to be able to reliably detect an approach of an object or a contact with the object, according to the first embodiment, a first edge 23 of the electrode configuration 20 and in particular corresponding contact edges of the individual touch electrodes 24 are on a lateral edge 25 of the upper side 22 of the Actuator 21 glued. As FIG. 3A also shows, the corresponding touch electrodes 24 extend, starting from the lateral edge 25 of the upper side 22 of the actuating element 21, over a lateral surface 26 of the actuating element 21 to an underside of the actuating element 21 opposite the upper side 22 .

According to the first embodiment, a distance between touch electrodes 24 arranged directly one after the other is again chosen such that a high resolution is achieved and at the same time the influence of one touch electrode by other touch electrodes is reduced. As FIG. 3A shows, this results in the distance between individual touch electrodes 24, which in turn are transparent electrodes according to the first embodiment, being as small as possible.

FIG. 3B shows a schematic perspective plan view of an underside 27 of the actuating member 21 according to the first embodiment. It can be seen here that the electrode configuration 20 is attached to the actuating member 21 in such a way that a second edge of the touch electrodes 24 is glued to the underside 27 . In particular, these are coupling regions 28 of the touch electrodes 24 that can be brought into a capacitive coupling with the corresponding counter-electrodes (not shown in FIG. 3B).

Also visible here are corresponding fitting elements 29 which can be inserted into corresponding recesses in the device, ie by means of which the actuating member 21 with the applied electrode configuration 20 can be connected to the complex device.

FIG. 4 shows a cross-sectional view of a capacitive switch arrangement 2 according to embodiments of the invention. Components and parts with the same function or construction as in FIG. 1 or FIG. 2 have the same reference numbers and are not explained separately.

As FIG. 2 shows, the capacitive switch arrangement 2 has an actuating element 16 on which the touch electrodes are applied. The touch electrodes can be glued or screwed onto the actuating element, for example.

A flexible printed circuit board 10 can also be seen, which is connected to the actuating element 16 by an adhesive connection. In particular, the flexible printed circuit board 10 is glued to the actuating member 16 in such a way that the coupling quality between a touch electrode and the counter-electrode that can be brought into a capacitive coupling with this touch electrode is high in each case. The fact that the coupling quality is high means in turn that the touch electrode and the corresponding counter-electrode are spaced apart from one another in such a way that signal transmission between the touch electrode and the corresponding counter-electrode is as optimal as possible and potential signal attenuations can be kept small.

With the capacitive switch arrangement 2 according to the embodiments of FIG. 4, an electrically conductive connection can thus be implemented in a simple manner even with complex touch surfaces, especially since the electrical connection and signal transmission are carried out by a plate capacitor is realized, the plates of which are each formed by the touch and the corresponding counter electrodes.

According to the embodiments of FIG. 4, the adhesive connection can also be a connection formed by a dielectric adhesive material. In addition, the flexible printed circuit board 10 can have an evaluation unit for evaluating signals picked up by the counter-electrodes.

Reference List

1 device

2 capacitive switch arrangement

3 touch electrode

4 counter electrode

5 evaluation unit

6 signal generator

7 control unit

8 sensor zone

9 Electrode Configuration

10 flexible circuit board

11 Electrode Configuration

12 surface

13 touch electrode

14 counter electrode

15 surface

16 actuator

20 Electrode Configuration

21 actuator

22 top

23 first edge

24 touch electrode

25 lateral edge

26 lateral surface

27 underside

28 docking area

29 shim d _ss distance d _SE distance

Claims

patent claims

1 . Electrode configuration for a capacitive switch arrangement, having at least two touch electrodes (3, 13, 24) and at least two counter-electrodes (4, 14), wherein the at least two touch electrodes (3, 13, 24) and the at least two counter-electrodes (4 ,14) are each arranged in a row in such a way that each of the at least two touch electrodes (3,13,24) can be brought into a capacitive coupling with one of the at least two counter-electrodes (4,14), and wherein a The distance between two touch electrodes (3,13,24) arranged directly one after the other is selected in such a way that a high resolution is achieved and at the same time the influence of one touch electrode (3,13,24) by other touch electrodes (3,13,24) is reduced .

2. Electrode configuration according to claim 1, wherein the distance between two touch electrodes (3,13,24) arranged directly one after the other is greater than or equal to 1 mm.

3. Electrode configuration according to claim 1 or 2, wherein the distance between two touch electrodes (3,13,24) arranged directly one after the other is selected in each case such that a number of touch electrodes (3,13,24) arranged in a predetermined area is maximized is, under the condition that at the same time an influence of a touch electrode (3,13,24) by other touch electrodes (3,13,24) is reduced.

4. Electrode configuration according to one of claims 1 to 3, wherein a distance between a touch electrode (3,13,24) and a counter-electrode (4,14) that can be brought into a capacitive coupling with this touch electrode (3,13,24) in each case is selected in such a way that a coupling quality between a touch electrode (3,13,24) and the counter-electrode (4,14) that can be brought into a capacitive coupling with this touch electrode (3,13,24) is high in each case.

5. Electrode configuration according to claim 4, wherein the distance between a touch electrode (3,13,24) and a counter-electrode (4,14) that can be brought into a capacitive coupling with this touch electrode (3,13,24) is greater than or equal to 0 .1 mm and less than or equal to 0.3 mm.

6. Electrode configuration according to one of claims 1 to 5, wherein the at least two touch electrodes (3, 13, 24) are each transparent electrodes.

7. Capacitive switch arrangement, wherein the capacitive switch arrangement (2) has an electrode configuration (20) according to any one of claims 1 to 6, an actuator (16,21) and a flexible circuit board (10), wherein the touch electrodes (13,24 ) are mounted on the actuator (16,21), and wherein the counter electrodes (14) are mounted on the flexible circuit board (10).

The capacitive switch assembly of claim 8, wherein the flexible circuit board (10) is bonded to the actuator (16) by an adhesive bond.

9. Device which has a capacitive switch arrangement (2) according to claim 7 or 8 and an evaluation unit (5) coupled to the counter-electrode electrodes (4) for detecting an actuation of the capacitive switch arrangement (2).