Touch and / or proximity-sensitive input device

Abstract

Touch and / or proximity sensitive input device, comprising: a control panel (10) with a functional section (11); a sensor film (12) with at least one capacitive sensor field (13), a carrier plate (17) with a sensor circuit (18) arranged on a side of the control panel (10) facing away from a user, wherein the at least one capacitive sensor field (13) is connected to the sensor circuit (18) via at least one electrical line (20a); and the sensor film (12) further comprises at least one antenna element (14) and an antenna circuit (19) is further provided on the carrier plate (17), wherein the at least one antenna element (14) is connected to the antenna circuit (19) via at least one further electrical line (20b), characterized in that the sensor circuit (18) and the antenna circuit (19) are connected to one another and are designed to deactivate the at least one capacitive sensor field (13) while the antenna element (14) is active.

Description

The present invention relates to a touch- and / or proximity-sensitive input device having a capacitive operating principle.Touch- and / or proximity-sensitive input devices (frequently also referred to as "touch control") are used in many electronic devices, in particular also in household appliances, which, by a user simply touching or approaching, trigger a specific switching process, for example, and / or change a device setting. In modern devices, there is also an ever-increasing need for the possibility of data exchange with mobile terminals. Thus, for example, a user can receive information from a household appliance at his mobile radio device or actuate a household appliance with his mobile radio device. Alternatively, customers can pay cashless in commercial applications such as laundry treatment appliances via their mobile radio device. For this purpose, the devices require, in addition to the input device, for example in the manner of a touch control, additionally a means for wireless communication.US 2014 / 0176819 A1 discloses an operating panel of a household appliance which has a touch-sensitive and / or proximity-sensitive input device and a means for wireless communication. The input device in the form of a capacitive sensor array is arranged on a flexible film on which an antenna element is additionally located.A method for producing a capacitive operating device, the capacitive measuring electrodes of which are arranged on a carrier film, is disclosed in DE 11 2013 006 446 T5.It is the object of the invention to provide a concept for combining a touch- and / or proximity-sensitive input possibility with a possibility for wireless data exchange, which can be realized with a simple and compact structure.This object is achieved by a touch- and / or proximity-sensitive input device having the features of claim 1.The touch- and / or proximity-sensitive input device of the invention contains an operating panel with a functional section, a sensor film with at least one capacitive sensor field and a carrier plate with a sensor circuit which is arranged on a side of the operating panel facing away from a user, wherein the at least one capacitive sensor field is connected to the sensor circuit via at least one electrical line, and is characterized in that the sensor film further has at least one antenna element and an antenna circuit is further provided on the carrier plate, wherein the at least one antenna element is connected to the antenna circuit via at least one further electrical line, wherein the sensor circuit and the antenna circuit are connected to one another and are configured to deactivate the at least one capacitive sensor field while the antenna element is active.According to the invention, it is proposed to use a sensor foil having at least one capacitive sensor field, in which an antenna element is also integrated, for a touch- and / or proximity-sensitive input device. By integrating the antenna element into the sensor foil, separate carriers or a larger carrier plate for mounting the antenna element can be dispensed with. In this way, a compact design of the input device, a reduced number of components and / or a simplified assembly / mounting of the input device can be achieved. In addition, the antenna is flexible due to the integration into the sensor film and can thus be more easily and better adapted to the geometry of the control panel, analogous to the capacitive sensor fields. Thus, the measurement accuracy of the sensors and the data exchange via the antenna can be improved.The sensor circuit and the antenna circuit are connected to one another and configured such that the at least one capacitive sensor array is deactivated while the antenna element is active. In this way, interference of the data exchange via the antenna by the sensors can be prevented.Alternatively or additionally, the frequencies, arrangements, dimensioning and / or spacings of the sensor arrays and of the antenna elements can also be adapted in such a way that mutual interference is prevented or at least minimized.The antenna element together with the antenna circuit is, for example, an NFC antenna (near field communication) or RFID antenna (radio frequency identification). The antenna element is preferably a structure made of an electrically conductive material, which is formed, for example, by printing or coating a carrier film.The sensor film has at least one capacitive sensor field, preferably an arrangement of a plurality of capacitive sensor fields. The sensor fields are each designed in the form of an electrode which is formed, for example, by printing or coating a carrier film with electrically conductive material. The carrier film is preferably transparent to light. The sensor field, together with, for example, a finger of a user, forms a capacitor via a dielectric (depending on the embodiment, for example, the control panel or a cover on the control panel), the capacitance of which capacitor is variable in accordance with the touching or non-touching or approaching or non-approaching. The change in the capacitance value correspondingly influences an output signal of the sensor circuit, which can be processed and evaluated by an evaluation electronics.The at least one sensor array and the at least one antenna element can be provided on the same side or on different sides of the sensor film.The antenna element is arranged on the sensor foil next to the at least one sensor field or the arrangement of sensor fields or around the at least one sensor field or the arrangement or a part of the arrangement of sensor fields. In either case, the antenna element and the sensor arrays are electrically isolated from each other.The control panel is preferably made of a plastic material (e.g. PC, PMMA). The control panel is preferably a dimensionally stable component and manufactured, for example, as an injection-molded part. The sensor film is preferably fastened to the control panel by means of adhesive bonding.In one embodiment variant of the invention, the sensor film is arranged on a side of the control panel facing away from a user. In this case, the control panel is preferably designed to be electrically non-conductive at least in the region of the functional section in order to form the dielectric of the capacitor. Alternatively or additionally, an electrically non-conductive cover can also be applied on the user side of the control panel.In this embodiment, an elastic pressure element is preferably arranged on the side of the control panel facing away from a user in order to press the sensor film against the control panel. In this way, the position of the sensor fields relative to the control panel is defined, whereby the measurement accuracy and reliability of the capacitive sensors are improved. The pressure element can be, for example, a foam plate (e.g. EPDM) which is supported against the carrier plate or its housing.In another embodiment variant of the invention, the sensor film is arranged on a side of the control panel facing a user. In this case, the sensor foil is preferably covered by an electrically non-conductive cover, which then forms the dielectric of the capacitor.In one configuration of the invention, the sensor film has at least one cutout in the region outside the at least one sensor array and preferably also outside the antenna element. Through these recesses, air can escape-in particular during the assembly of the input device but also in the assembled state-from the intermediate spaces between the sensor film and the control panel and / or the cover, whereby air inclusions (e.g. air cushions, air bubbles) in the capacitors of the sensors can be avoided. In this embodiment, the control panel preferably additionally has at least one venting channel which is connected to the at least one cutout in the sensor film. The sensor fields and the antenna element are thus closer to the user interface of the input device and their modes of operation are not disturbed by air inclusions.In a further embodiment of the invention, the operating screen has, in its functional section, on its side facing the sensor film, in the region outside the at least one sensor array and preferably also outside the antenna element, at least one depression for forming a free space between the sensor film and the operating screen. These depressions also allow air to escape from the intermediate spaces between the sensor film and the control panel-in particular during the assembly of the input device but also in the assembled state-as a result of which air inclusions in the capacitors of the sensors can be avoided.In a further embodiment of the invention, the control panel is raised on its side facing the sensor film in the region of the at least one sensor array and preferably also in the region of the antenna element. This measure makes it possible to ensure close contact between the operating panel and the sensor fields or the antenna element, as a result of which the measurement accuracy and reliability of the capacitive sensors or of the antenna can be improved.The carrier plate, which is preferably designed as a printed circuit board, can, depending on the embodiment, either be directly engaged with the control panel or be arranged in a housing engaged with the control panel.In a further embodiment of the invention, at least one lighting means, preferably in the form of an LED, and / or at least one display device (e.g. display, etc.) are arranged on the carrier plate and the sensor film and the functional section of the control panel are configured to be at least partially transparent to light. The light transmission of the sensor film or of the control panel can preferably be achieved by a corresponding choice of material or by means of perforations.In a further embodiment of the invention, the input device can additionally be configured with a decorative film. This decorative film is arranged, for example, on the side of the sensor film facing a user. With this decorative film, for example, the control buttons defined by the sensor fields can be marked with symbols. Alternatively, the sensor film itself can also be printed or coated with symbols etc., i.e. the decorative film can be combined with the sensor film to form a component.In a further embodiment of the invention, the input device can additionally be configured with a cover layer or cover plate. This cover layer is preferably arranged on the side of the operating film facing a user and can be provided with a desired design (company logo, etc.), for example, by the end manufacturer of the appliance in which the input device is installed.The above-described input device of the invention can be used in an advantageous manner in electronic domestic appliances (hobs, cookers, dishwashers, washing machines, tumble dryers, refrigerators and / or freezers, etc.) or commercial laundry treatment appliances (e.g. washing machines, tumble dryers, etc.).The above and other features and advantages of the invention will become more fully understood from the following description of preferred, non-limiting embodiments with reference to the accompanying drawings. In the figure, in part, diagrammatically show: FIG. 1 is an exploded perspective view of an input device according to a first embodiment of the invention; FIG. 2 shows various partial sectional views of the input device of FIG. 1 in FIGS. 2A and 2B ; FIG. 3 shows a plan view of a sensor film for an input device according to the invention according to a first embodiment; FIG. 4 shows a plan view of a sensor film for an input device according to the invention according to a second embodiment; FIG. 5 is an exploded perspective view of an input device according to a second embodiment of the invention; FIG. 6 is an exploded perspective view of an input device according to a third embodiment of the present invention; FIG. 7 is an exploded perspective view of an input device according to a fourth embodiment of the present invention; FIG. 8 shows a perspective view of a sensor film for an input device according to the invention according to a further embodiment; and FIG. 9 shows a partial sectional view of an input device according to the invention with a sensor film from FIG. 8.Referring to FIGS. 1 and 2, the configuration of an input device according to a first embodiment of the invention will be described in detail.The input device has an operating panel 10 made of a plastic material (e.g. PC or PMMA), which is provided with a functional section 11. On the side of the control panel 10 facing a user (on the left in FIGS. 1 and 2 ), a sensor film 12 is arranged. As shown in FIG. 2B, the control panel 10 is provided in the functional section 11 with a depression 24 bfor receiving this sensor film 12. The sensor film 12 can be glued to the control panel 10 in this depression 24 b.As explained later, the sensor foil 12 is equipped with an arrangement of a plurality of capacitive sensor fields 13 in order to form a touch- and / or proximity-sensitive input device with a capacitive functional principle. In addition, the sensor foil 12 is equipped with an antenna element 14 in order to enable wireless data exchange with a mobile telephone of a user, for example.As shown in FIG. 1, a decorative film 15 is optionally also provided on the side of the sensor film 12 facing the user. This decorative sheet 15 is transparent and contains symbols for identifying the operating keys defined by the sensor panels 13 and backlit information displays. Alternatively, the symbols can also be printed or coated directly onto the sensor film 12.Finally, on the side facing a user, a cover layer 16 is also provided, which covers the sensor film 12 and-if present-also the decorative film 15. As shown in FIG. 2B, the control panel 10 is provided in the functional section 11 with a depression 24 afor receiving this cover layer 16. The depression 24 bfor the sensor foil 12 is located within this depression for the cover layer 16. It is electrically non-conductive and its layer thickness is at least 2 mm to form a dielectric for the capacitive sensors and is at least partially transparent.On the side of the control panel 10 facing away from a user (on the right in FIGS. 1 and 2 ), a carrier plate 17 in the form of a printed circuit board is arranged. The carrier plate 17 is fastened to the control panel 10 for example by means of screwing or snapping in. On the carrier plate 17 a sensor circuit 18 and an antenna circuit 19 are provided, which are electrically conductively connected to the sensor fields 13 or the antenna element 14 on the sensor foil 12 by means of connecting lines in order to actuate the sensor fields 13 or the antenna element 14 and evaluate the measurement signals thereof. The connecting lines 20 are led through an aperture 21 in the control panel 10. The sensor circuit 18 and the antenna circuit 19 are connected to a device controller of the respective device in which the input device is installed, which device controller can likewise be arranged on the carrier plate 17 or separately therefrom.As shown in FIG. 2A, the operating panel 10 has a plurality of depressions 22 in its functional section 11 on its side facing a user.As shown in FIGS. 2A and 2B, a plurality of lighting means 23 in the form of LEDs are mounted on the carrier plate 17. The functional section 11 of the control panel 10 is accordingly provided with a plurality of apertures / light channels 30 in order to be transparent to light. In this context, FIG. 2A illustrates LEDs 23 for a 7-segment display, while FIG. 2B shows LEDs 23 for identifying the operating keys defined by the sensor fields 13.Referring now to Figures 3 and 4, two embodiments of a sensor sheet for an input device of the invention will be described in more detail. The sensor foils of Figures 3 and 4 may be used, for example, in the input devices of Figures 1-2, 5, 6, 7.FIGS. 3 and 4 each show a sensor foil 12 with an arrangement of eight capacitive sensor fields 13, the electrode surfaces of which are connected via electrical lines 20 ato the sensor circuit 18 on the carrier plate 17, and an antenna element 14, the line structure of which is connected via further electrical lines 20 bto the antenna circuit 19 on the carrier plate 17. The electrically conductive elements of the sensor arrays 13 and of the antenna element 14 are separated from one another and are thus electrically insulated from one another. The frequencies and distances are selected so that no mutual interference arises. Alternatively, the sensor circuit 18 and the antenna circuit 19 can also be connected to one another and designed such that the capacitive sensor arrays 13 are switched off while the antenna element 14 is active.In the embodiment variant of FIG. 3, the antenna element 14 is positioned next to the arrangement of the sensor arrays 13. In the embodiment variant of FIG. 4, the antenna element 14 extends around the arrangement of the sensor arrays 13. In the case of FIG. 4, the electrical lines 20 bfor connecting the sensor arrays 13 preferably run substantially perpendicular to the electrically conductive structure of the antenna element 14, in order to minimize interference effects.The sensor arrays 13 and the antenna element 14 can be provided either on the same side of a carrier film or on different sides of a carrier film.Referring now to FIG. 5, the structure of an input device according to a second embodiment of the invention will be described in detail. Identical or corresponding components are identified with the same reference numerals as in the first exemplary embodiment.The input device of FIG. 5 differs from the first exemplary embodiment according to FIGS. 1 and 2 in particular in that the sensor film 12 is arranged on the side of the control panel 10 facing away from a user.Although not illustrated, a decorative film 15 can optionally also be provided in the exemplary embodiment of FIG. 5 ; in the embodiment of FIG. 5, for example, between the sensor film 12 and the control panel 10 or between the cover layer 16 and the control panel 10.As illustrated in FIG. 5, a housing 25 for accommodating the substrate 17 may also be provided with the sensor circuit 18 and the antenna circuit 19. In this case, the housing 25 is fastened to the control panel 10, for example by means of screwing or snapping in. The sensor film 12 is fastened to the control panel 10 by means of adhesive bonding.The exemplary embodiment of FIG. 5 corresponds to the first exemplary embodiment of FIGS. 1 and 2 with its possible variants.Referring now to FIG. 6, the structure of an input device according to a third embodiment of the invention will be described in detail. Identical or corresponding components are identified with the same reference numerals as in the preceding exemplary embodiments.The input device of FIG. 6 differs from the second exemplary embodiment according to FIG. 5 in that an elastic pressure element 26 is arranged between the housing 25 for the carrier plate 17 and the sensor film 12, said elastic pressure element being supported against the housing 25 and pressing the sensor film 12 against the control panel 10. The elastic pressing member 26 is, for example, a foam plate made of, for example, EPDM (ethylene-propylene-diene rubber). The pressure element has, for example, a layer thickness of approximately 2 mm. When using such a pressure element 26, it is possible to dispense with adhesive bonding of the sensor film 12 to the control panel 10.The exemplary embodiment of FIG. 6 corresponds to the second exemplary embodiment of FIG. 5 with its possible variants.Referring now to FIG. 7, the structure of an input device according to a fourth embodiment of the invention will be described in detail. Identical or corresponding components are identified with the same reference numerals as in the preceding exemplary embodiments.In the exemplary embodiment of FIG. 7, at least one diffusion element 27 is additionally provided in the functional section 11 of the control panel 10 in order to scatter the light conducted through apertures in the control panel.This embodiment can be combined with all the preceding exemplary embodiments. That is, the support plate 17 may be attached to the control panel 10 or accommodated in a housing 25 attached to the control panel 10, and the sensor film 12 may be attached to the control panel 10 by means of adhesive bonding or pressed against the control panel 10 by an elastic pressing member 26.Referring now to Figures 8 and 9, a further embodiment of a sensing foil and its integration into an input device of the invention will be described in more detail. Identical or corresponding components are identified with the same reference numerals as in the preceding exemplary embodiments.The sensor foil 12 of FIG. 8 is provided with an arrangement of sixteen capacitive sensor fields 13, the electrode surfaces of which are connected via electrical lines 20 ato the sensor circuit 18 on the carrier plate 17, and with an antenna element 14, the line structure of which is connected via further electrical lines 20 bto the antenna circuit 19 on the carrier plate 17. In the embodiment of Fig. 8, the antenna element 14 is positioned adjacent to the array of sensor arrays 13. Alternatively, the antenna element 14 can also run around the arrangement of the sensor arrays 13.The exemplary embodiment of the sensor film 12 from FIG. 8 differs from the embodiments according to FIGS. 3 and 4 in that it comprises a plurality of recesses 28. As illustrated in FIG. 9, these recesses 28 can be connected to venting channels 29 in order to allow air to escape between the sensor film 12 and the control panel 10 and thus prevent air inclusions. The ventilation channels 29 can be part of the control panel 10, for example, or can be mounted as separate elements on the carrier plate 17. Furthermore, the recesses 28 can serve for the passage of light.The sensor foil 12 of FIG. 8 can also be used in all the above-described embodiments of the input device of the invention.As shown in FIG. 9, the control panel 10 can also have light channels 30 in order to conduct light from lighting means 23 on the carrier plate 17 through the control panel 10. The sensor foil 12 is likewise provided with recesses at the locations of the light channels 30. At the end of the light channels 30, a diffusion element 27 can then be mounted on the control panel 10, for example, as illustrated in FIG. 7. This embodiment variant is advantageous in particular when using control panels made of an opaque material.

Claims

Touch- and / or proximity-sensitive input device, comprising: an operating panel (10) having a functional section (11); a sensor film (12) having at least one capacitive sensor field (13), a carrier plate (17) having a sensor circuit (18) which is arranged on a side of the operating panel (10) facing away from a user, wherein the at least one capacitive sensor field (13) is connected to the sensor circuit (18) via at least one electrical line (20a); and the sensor film (12) further comprises at least one antenna element (14) and an antenna circuit (19) is further provided on the carrier plate (17), wherein the at least one antenna element (14) is connected to the antenna circuit (19) via at least one further electrical line (20b), characterized in that the sensor circuit (18) and the antenna circuit (19) are connected to one another and are configured to deactivate the at least one capacitive sensor array (13) while the antenna element (14) is active.Input device according to claim 1, wherein the antenna element (14) is arranged on the sensor foil (12) next to the at least one sensor array (13) or around the at least one sensor array (13).Input device according to claim 1 or 2, in which the sensor film (12) is arranged on a side of the control panel (10) facing away from a user and the control panel (10) is configured to be electrically non-conductive in the region of the functional section (11).Input device according to claim 3, wherein an elastic pressure element (26) is arranged on the side of the control panel (10) facing away from a user in order to press the sensor film (12) against the control panel (10).Input device according to claim 1 or 2, wherein the sensor foil (12) is arranged on a side of the control panel (10) facing a user and is covered by an electrically non-conductive cover (15, 16).Input device according to one of the preceding claims, in which the sensor film (12) has at least one cutout (28) in the region outside the at least one sensor array (13) and preferably also outside the antenna element (14).Input device according to claim 6, wherein the control panel (10) has at least one venting channel (29) which is connected to the at least one recess (28) in the sensor film (12).Input device according to one of the preceding claims, in which the operating screen (10) has, in its functional section (11), on its side facing the sensor film (12), in the region outside the at least one sensor field (13) and preferably also outside the antenna element (14), at least one depression (22) for forming a free space between the sensor film (12) and the operating screen (10).Input device according to one of the preceding claims, in which the control panel (10) is raised on its side facing the sensor film (12) in the region of the at least one sensor array (13) and preferably also in the region of the antenna element (14).Input device according to one of the preceding claims, in which the carrier plate (17) is directly in engagement with the control panel (10) or is arranged in a housing (25) in engagement with the control panel (10).Input device according to one of the preceding claims, in which at least one lighting means (23) and / or at least one display device are arranged on the carrier plate (17), and the sensor film (12) and the functional section (11) of the control panel (10) are designed to be at least partially transparent to light.Use of a touch- and / or proximity-sensitive input device according to one of Claims 1 to 11 for an electronic domestic appliance or a commercial laundry treatment appliance.

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