Abstract:
An operating device, in particular for electronic household appliances, includes a cover plate with an operating portion, a transmitter for emitting electromagnetic radiation, a receiver for registering electromagnetic radiation, and control electronics for evaluating measurement signals produced by the receiver. The operating portion is at least partly elastically deformable and/or movable by an action of force from the direction of a user side of the cover plate and it at least partly reflects the radiation emitted by the transmitter. The receiver is disposed and/or configured in such a way that it facilitates a spatially resolved registration of the radiation reflected by the operating portion in such a way that the control electronics can detect an actuation of the operating portion in a manner dependent on a registration location of the reflected radiation. An electronic household appliance having at least one operating device is also provided.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This is a continuation application, under 35 U.S.C. §120, of copending International Application PCT/EP2015/000846, filed Apr. 23, 2015, which designated the United States; this application also claims the priority, under 35 U.S.C. §119, of German Patent Application DE 10 2014 007 036.0, filed May 13, 2014; the prior applications are herewith incorporated by reference in their entirety. 
     
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0002]    The present invention relates to an operating device, in particular an operating device for electronic household appliances. The invention also relates to an electronic household appliance having the operating device. 
         [0003]    Different types of operating elements with different functionalities are known for operating devices. By way of example, in the case of operating elements embodied as pushbuttons, it is possible to differentiate between contact and/or proximity sensitive pushbuttons (so called “touch control”) and pushbuttons actuated by the action of force. Such pushbuttons are each realizable with various constructions and functionalities. 
         [0004]    In that context, capacitive pushbuttons (see, for example, German Patent Application DE 10 2011 121 897 A1), inductive pushbuttons (see, for example, European Patent EP 2 529 484 B1, corresponding to U.S. Patent Application US 2011/0187204), and piezoelectric pushbuttons, in particular, are known in addition to those with a mechanical actuation element in the case of pushbuttons actuated by the action of force. In general, those specific pushbuttons require high manufacturing and assembly accuracy with small tolerance ranges. 
         [0005]    Contact and proximity sensitive pushbuttons often have a sensor system based on a capacitive or inductive functional principle. In the case of metallic operating faceplates, those pushbuttons then need to be provided with additional measures for electrical insulation. Other contact and/or proximity sensitive pushbuttons with an optical sensor system (see, for example, German Patent DE 10 2006 004 979 B4, corresponding to U.S. Pat. No. 9,190,999) require an operating faceplate made of a transparent material or with perforations, as a matter of principle. 
       SUMMARY OF THE INVENTION 
       [0006]    It is accordingly an object of the invention to provide an operating device, in particular for an electronic household appliance, and an electronic household appliance having the operating device, which overcome the hereinafore-mentioned disadvantages of the heretofore-known devices and appliances of this general type and which provide a pushbutton actuated by the action of force, which has a reliable functionality. 
         [0007]    With the foregoing and other objects in view there is provided, in accordance with the invention, an operating device, in particular for an electronic household appliance, comprising a cover plate with a user side facing a user, the cover plate having an operating portion; at least one transmitter for emitting electromagnetic radiation and at least one receiver for registering electromagnetic radiation; and control electronics for evaluating measurement signals produced by the at least one receiver. The operating portion of the cover plate is configured in such a way that it is at least partly elastically deformable and/or movable by an action of force from the direction of the user side of the cover plate and that it at least partly reflects the radiation emitted by the at least one transmitter. Moreover, the at least one receiver is disposed and/or configured in such a way that it facilitates a spatially resolved registration of the radiation reflected by the operating portion. The control electronics can then detect an actuation of the operating portion in a manner dependent on a registration location of the reflected radiation. 
         [0008]    In the operating device according to the invention, minimal deformations or travels of the operating portion are sufficient to be able to register an actuation by the user since very different deflections of electromagnetic radiation are already effected in the case of very small changes of the reflection location at the operating portion. The actuation of the operating portion can therefore be identified very reliably by the control electronics. 
         [0009]    Moreover, the tolerances during manufacturing and assembly of the components in the case of an operating device with such a construction may be increased in comparison with conventional pushbuttons actuated by the action of force with a capacitive, inductive or piezoelectric functionality. This is achieved by the very different registration location on the receiver which is already effected in the case of minimal changes in the reflection location at the operating portion. This can also reduce the susceptibility to errors and thus increase the reliability of the operating device. 
         [0010]    The operating device of the invention facilitates a retrospective adaptation of the control electronics to the mechanical components such as, in particular, the cover plate with the operating portion. 
         [0011]    Since the registration of a relative change in the registration location of the reflected radiation at the receiver (in contrast to the registration of an absolute value) suffices for detecting an actuation of the operating portion, it is also possible to dispense with a calibration process in the operating device according to the invention. 
         [0012]    In this context, the cover plate may be manufactured from any material, with any dimensions and any construction. The cover plate is preferably an operating faceplate, for example of an electronic household appliance. 
         [0013]    Preferably, the operating portion has an integral or one-piece embodiment with the cover plate, it is inserted as a separate component into the cover plate or it is connected as a separate component to the cover plate. For the user, the operating portion defines the operating element of the operating device which needs to be pressed for actuation. Preferably, the operating portion is marked for the user, preferably by a special shaping of the user side thereof (haptic labeling), a label with colors and/or symbols, backlighting, an identifiable delimitation from the remainder of the cover plate and the like. 
         [0014]    The operating portion is at least partly elastically deformable and/or movable by an action of force from the direction of the user side of the cover plate. The elastic deformability is preferably achieved by a specific material selection and/or specific dimensioning of the operating portion. Preferably, the elastic movability can be realized by a resilient bearing of the operating portion in a perforation in the cover plate. 
         [0015]    The electromagnetic radiation which is emitted by the at least one transmitter and registered by the at least one receiver is preferably optical radiation, preferably in the visible or infrared wavelength range. With respect to the electromagnetic radiation registrable thereby, the at least one receiver is tuned to the electromagnetic radiation emitted by the at least one transmitter. Preferably, the respective wavelength ranges substantially correspond or have a significant overlap region. 
         [0016]    The at least one transmitter is preferably a light-emitting diode (LED), a laser diode, an incandescent lamp, a halogen lamp or the like. However, the at least one transmitter can also be realized by ambient light which can reach the rear side of the operating portion through an appropriate opening, for example in the appliance housing or in the cover plate. 
         [0017]    The at least one receiver facilitates a spatially resolved registration of the reflected radiation. Preferably, the at least one receiver is exactly one receiver with a spatially resolving functionality or the at least one receiver is formed by a plurality of receivers disposed substantially next to one another. Accordingly, the at least one receiver is preferably selected from a CCD chip, an active pixel sensor, photodiodes, phototransistors, ambient light sensors and the like. 
         [0018]    The operating portion is configured in such a way that it is able to at least partly reflect the radiation emitted by the at least one transmitter. This reflection behavior of the operating portion is preferably achieved by a specific material selection of the operating portion, by a specific surface structure of the rear side of the operating portion, by a specific surface treatment (preferably a coating, etc.) of the rear side of the operating portion or the like. 
         [0019]    Despite its optical functionality, the operating device of the invention can advantageously also be used in the case of cover plates which are substantially opaque to the respective electromagnetic radiation. In particular, the operating portion may also be configured to be substantially opaque to the radiation emitted by the at least one transmitter. 
         [0020]    In addition to the operating portion which is actuatable by an action of force and optically evaluable, the operating device may also have further operating elements with other functionalities. In this case, use can be made, in particular, of other pushbuttons and contact and/or proximity sensitive buttons. 
         [0021]    In a preferred configuration of the invention, the cover plate has a plurality of operating portions, each of which is configured to be elastically deformable and/or movable by an action of force from the direction of the user side of the cover plate. Therefore, the operating device has a plurality of operating elements which are actuatable by a user. 
         [0022]    In this case, preferably, at least one common transmitter and/or at least one common receiver may be provided for a plurality of (i.e. for at least two or even all of) the plurality of operating portions. 
         [0023]    In one configuration of the invention, provision is moreover made for at least one optical waveguide for transporting the radiation emitted by the at least one transmitter to the operating portion, to one of the plurality of operating portions or to at least two of the plurality of operating portions. This configuration may be facilitated in a compact manner in the region of the operating portion or the operating portions since the at least one transmitter may be placed at a different location. The at least one optical waveguide can preferably transport the radiation to an operating portion or—by way of a plurality of decoupling points—to a plurality of operating portions. 
         [0024]    In one configuration of the invention, a plurality of receivers, which are assigned to various operating portions, and/or a plurality of transmitters, which are assigned to various operating portions, may be operated in a clocked manner by the control electronics. In this manner, it may be possible to differentiate actuations of different operating portions from one another, despite a common use of a transmitter or receiver. 
         [0025]    In one configuration of the invention, at least two of the plurality of operating portions may have at least one reflector for reflecting the radiation emitted by the at least one transmitter, wherein the reflectors assigned to various operating portions have different angles of reflection. In this configuration, transmitters or receivers may advantageously be used together for a plurality of operating portions. 
         [0026]    In one configuration of the invention, at least one lens may be provided. The lens is assigned together to at least two of the plurality of operating portions and deflects the radiation reflected by various operating portions to a different extent. In this configuration too, transmitters or receivers may advantageously be used together for a plurality of operating portions. 
         [0027]    With the objects of the invention in view, there is concomitantly provided an electronic household appliance comprising at least one above-described operating device of the invention. 
         [0028]    The electronic household appliance is preferably a laundry treatment appliance (washing machine, tumble dryer, etc.), a dishwasher, a cooling and/or freezing appliance (refrigerator, freezer, etc.), a hob or cooktop, an oven, a microwave oven, an extractor or exhaust fan or the like. 
         [0029]    Other features which are considered as characteristic for the invention are set forth in the appended claims. 
         [0030]    Although the invention is illustrated and described herein as embodied in an operating device, in particular for an electronic household appliance, and an electronic household appliance having the operating device, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
         [0031]    The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0032]      FIGS. 1A and 1B  are very simplified schematic and block diagrams illustrating the functional principle of an operating device in accordance with a first embodiment variant of the invention; 
           [0033]      FIG. 2  is a diagrammatic, sectional view of an operating device including a plurality of operating portions in accordance with one exemplary embodiment of the invention; 
           [0034]      FIG. 3  is a top-plan view of an operating device including a plurality of operating portions in accordance with a further exemplary embodiment of the invention; 
           [0035]      FIG. 4  is a top-plan view of an operating device including a plurality of operating portions in accordance with a further exemplary embodiment of the invention; 
           [0036]      FIG. 5  is a sectional view of an operating device including a plurality of operating portions in accordance with an even further exemplary embodiment of the invention; 
           [0037]      FIG. 6  is a sectional view of an operating device including a plurality of operating portions in accordance with an even further exemplary embodiment of the invention; and 
           [0038]      FIGS. 7A and 7B  are very simplified, fragmentary, sectional views illustrating the functional principle of an operating device in accordance with a second embodiment variant of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0039]    Referring now in detail to the figures of the drawings, showing preferred, non-restrictive exemplary embodiments of the invention, and first, particularly, to  FIG. 1  thereof, there is initially seen an illustration of a basic functionality of an operating device in accordance with a first embodiment variant of the invention. In this case, a state without actuation by a user is depicted in a partial illustration in  FIG. 1A , while a state with actuation by the user is depicted in a partial illustration in  FIG. 1B . 
         [0040]    The operating device includes a cover plate  10 , for example in the form of an operating faceplate of e.g. an apparatus or an electronic household appliance. This cover plate  10  has a user side  10   a  (at the top in  FIG. 1 ), facing a user, which corresponds to the outer side of the operating faceplate or of the appliance, and a rear side  10   b  (at the bottom in  FIG. 1 ), facing away from a user, which corresponds to the inner side of the operating faceplate or of the appliance. By way of example, the cover plate  10  is manufactured from a plastic or metal. 
         [0041]    This cover plate  10  has at least one operating portion  12  that defines an operating element for the user which may be actuated by the user. The operating portion  12  is integrated into or is formed as one piece with the cover plate  10  or it has an integral embodiment therewith or it is inserted therein as a separate component and optionally connected therewith. As the comparison of the partial illustrations in  FIGS. 1A and 1B  shows, the operating portion  12  has an elastically deformable configuration provided by an action of force F from the direction of the user side  10   a , for example by a finger of the user. That is to say, after the action of the force F is completed, the operating portion  12  returns into its initial state, which is indicated in the partial illustration in  FIG. 1A . 
         [0042]    The operating portion  12  is preferably labeled for the user, so that the user can find it more easily and is able to identify the functionality thereof. To this end, the operating portion  12 , or the outside thereof, may itself be labeled or the cover plate  10  may be labeled in the vicinity of the operating portion  12 . By way of example, labeling is brought about optically by colors and/or symbols, haptically by surface structures, electrically by backlighting or signal lamps, or the like. 
         [0043]    The operating device furthermore has at least one transmitter  16 , for example in the form of an LED, and at least one receiver  18 , for example in the form of a CCD chip. The transmitter  16  emits electromagnetic radiation, preferably light in the visible or infrared wavelength range, and the receiver  18  registers electromagnetic radiation of the same wavelength range. In this case, the at least one receiver  18  is configured to register radiation with spatial resolution. This means that a single receiver has such a capability (e.g. CCD chip, sensor array, etc.) or a plurality of receivers (e.g. photodiodes, phototransistors, etc.) are disposed next to one another and evaluated together. 
         [0044]    The at least one transmitter  16  and the at least one receiver  18  are connected to control electronics  20 . By way of example, the control electronics  20  have a microcontroller or are formed by a microcontroller. The control electronics  20  actuate the at least one transmitter  16 , i.e. the control electronics only switch the transmitter on and off in the simplest case or operate the transmitter e.g. in a clocked manner. Moreover, the control electronics  20  evaluate measurement signals generated by the at least one receiver  18  in order to be able to detect an actuation of the operating portion  12  by a user. 
         [0045]    As elucidated in the partial illustrations in  FIGS. 1A and 1B , radiation E emitted by the transmitter  16  is incident on the operating portion  12 , or the rear side thereof, and reflected there. Radiation R 1 , R 2  reflected at the operating portion  12  is then incident on the receiver  18  and registered by the latter. The receiver  18  generates corresponding measurement signals which are evaluated by the control electronics  20 . In the initial state shown in the partial illustration in  FIG. 1A , i.e. without actuation of the operating portion  12  by the user, the operating portion  12  is in its non-deformed initial state and reflects the radiation R 1  to the receiver  18 . In the actuation state shown in the partial illustration in  FIG. 1B , i.e. in the case of the user exerting a force F onto the operating portion  12 , the operating portion  12  is deformed and reflects the radiation R 2  to the receiver  18 . A comparison between the two partial illustrations in  FIGS. 1A and 1B  shows that there is a very clear change in the registration location of the reflected radiation R 2 , even in the case of a relatively small deformation of the operating portion  12 . This relative change of the registration location is registered by the spatially resolving receiver  18 , and therefore the control electronics  20  can register an actuation of the operating portion  12 . 
         [0046]    The registration of a relative change of the registration location at the receiver  18  is sufficient for the evaluation by the control electronics  20 . Absolute measurement values for the change are not required, but they may likewise be registered and evaluated in specific embodiments. The registration of only the relative change also minimizes the requirements on the dimensional and position accuracies of the individual components or increases the allowed tolerance ranges during manufacturing and during assembly of these components. 
         [0047]      FIG. 2  shows a first exemplary embodiment of an operating device according to the invention, which works according to the basic principle of  FIG. 1  explained above. 
         [0048]    As is indicated in  FIG. 2 , the transmitters  16  and the receivers  18  are disposed on a carrier plate  14 , for example in the form of a printed circuit board. By way of example, the carrier plate  14  is disposed substantially parallel to and behind the cover plate  10  at a small distance. The control electronics  20  may likewise be disposed on this carrier plate  14 . 
         [0049]    In this exemplary embodiment, the operating device has two operating elements, i.e. the cover plate  10  is equipped with two operating portions  12   a ,  12   b . On one hand, a common transmitter  16  is provided for both operating portions  12   a ,  12   b , and the transmitter emits radiation in the direction of both operating portions  12   a ,  12   b . On the other hand, at least one (dedicated) receiver  18   a ,  18   b  ( 18   n ) is provided for each one of the two operating portions  12   a ,  12   b.    
         [0050]    In a development of the exemplary embodiment depicted in  FIG. 2 , provision can naturally also be made, on one hand, for more than two operating portions  12   a ,  12   b  in the cover plate  10  which are irradiated by a common transmitter  16 . On the other hand, the exemplary embodiment of  FIG. 2  can also be reduced to a single operating portion  12 . 
         [0051]      FIG. 3  shows a second exemplary embodiment of an operating device according to the invention, which works according to the aforementioned basic principle. 
         [0052]    In this exemplary embodiment, the at least one transmitter  16  is disposed at a distance from the plurality of operating portions  12   a ,  12   b , . . . of the cover plate  10 . Provision is made for an optical waveguide  22  with a suitable form and dimensions for transporting the radiation emitted by the at least one transmitter  16  to the individual operating portions  12   a ,  12   b . . . .    
         [0053]    The radiation coupled into the optical waveguide  22  by the at least one transmitter  16  may be decoupled from the optical waveguide  22  in e.g. at the region of the operating portions  12   a ,  12   b , . . . . The radiation reflected at the operating portions  12  can then be registered by one or more receivers  18 . By way of example, the change in the registration location when actuating the operating portions  12   a ,  12   b , . . . is effected in a direction across the longitudinal extent of the optical waveguide  22  in such a way that, in the top view of  FIG. 3 , the receiver or receivers  18   a ,  18   b , . . . may be positioned next to the optical waveguide  22 . 
         [0054]      FIG. 4  shows a third exemplary embodiment of an operating device according to the invention, which works according to the aforementioned basic principle. 
         [0055]    In this exemplary embodiment, the cover plate  10  has a field of n operating portions  12   a , . . .  12   n , which are disposed e.g. in a matrix-like manner (see  FIG. 4 ) or along a line. At least one transmitter  16  is provided in  FIG. 4  for each row (or, more generally, each subgroup) of operating portions  12   n . Optionally, the plurality of transmitters  16  for the various rows or subgroups of operating portions  12   n  can also be operated in a clocked manner by the control electronics  20 . 
         [0056]    Further exemplary embodiments are described below on the basis of  FIGS. 5 and 6 , in which the numbers of transmitters and receivers can be kept as small as possible, despite a plurality of operating portions  12   n.    
         [0057]    In the exemplary embodiment of  FIG. 5 , a reflector  24   a ,  24   b , ( 24   n ) . . . is disposed in each case at the rear side of a plurality of operating portions  12   a ,  12   b , . . . . The reflectors  24   a ,  24   b , . . . of the various operating portions  12   a ,  12   b , . . . are irradiated by a common transmitter  16 . 
         [0058]    The reflectors  24   a ,  24   b , . . . of the various operating portions  12   a ,  12   b , . . . have different configurations than one another and/or are aligned differently in such a way that they have different angles of reflection. As a result, the radiation emitted by the transmitter  16  is reflected at the reflectors  24   a ,  24   b , . . . onto a common spatially resolving receiver  18  (or, alternatively, a group of receivers), despite their spaced apart positions. In this case, the reflected radiation for the various operating portions  12   a ,  12   b , . . . migrate over different registration location regions of the receiver  18 , which are optionally actuated or evaluated in a clocked manner by the control electronics  20  in such a way that the actuations of the various operating portions  12   a ,  12   b , . . . can be differentiated from one another. 
         [0059]    In the exemplary embodiment of  FIG. 6 , a lens  26  is disposed in the beam path between the plurality of operating portions  12   a ,  12   b , . . . and the common receiver  18  (or, alternatively, a group of receivers). This lens  26  is configured and disposed in such a way that the radiation reflected by the various operating portions  12   a ,  12   b , . . . are deflected to a different extent. As a result, the radiation reflected by the operating portions  12   a ,  12   b , . . . are focused onto the common receiver  18  with the aid of the lens  26 , despite the spaced apart positions thereof on the cover plate  10 . In this case, the radiation reflected by the various operating portions  12   a ,  12   b , . . . migrates over different registration location regions of the receiver  18 , which are optionally actuated or evaluated in a clocked manner by the control electronics  20  in such a way that the actuations of the various operating portions  12   a ,  12   b , . . . can be differentiated from one another. 
         [0060]    The basic functionality of an operating device in accordance with the second embodiment variant will now be explained in more detail on the basis of  FIGS. 7A and 7B . In this case, the partial illustration in  FIG. 7A  shows the state without actuation by the user, while the partial illustration in  FIG. 7B  depicts the state in the case of actuation by the user. 
         [0061]    In  FIGS. 7A and 7B , the same or corresponding components are denoted by the same reference signs as in  FIGS. 1 to 6 . Furthermore, the exemplary embodiments of  FIGS. 2 to 6 , described above, can be transferred to the embodiment variant of  FIGS. 7A and 7B  without difficulty by a person skilled in the art. 
         [0062]    The second embodiment variant of  FIGS. 7A and 7B  differs from the first embodiment variant of  FIG. 1  by the configuration of the operating portion  12  in the cover plate  10 . While the operating portion  12  in  FIGS. 1A and 1B  has an elastically deformable configuration provided by an action of force F by a user, the operating portion in the embodiment variant of  FIGS. 7A and 7B  is movable by an action of force F by a user. 
         [0063]    To this end, the operating portion  12  is preferably manufactured as a separate component from the cover plate  10  and mounted in a movable manner in a recess or perforation in the cover plate  10 . In the case of an actuation of the operating portion  12 , the latter is pressed into the cover plate  10  and displaced inwardly, as elucidated in the partial illustration in  FIG. 7B . After the action of force F has been terminated, the operating portion  12  returns into its initial position, which is indicated in the partial illustration in  FIG. 7A . By way of example, this is carried out with the aid of an elastic spring element, which pretensions the operating portion in its initial position. 
         [0064]    As is elucidated in the partial illustrations in  FIGS. 7A and 7B , the radiation E emitted by the transmitter  16  is incident on the operating portion  12 , or the rear side thereof, and reflected there. The radiation R 1 , R 2  reflected at the operating portion  12  is then incident on the receiver  18  and registered by the latter. The receiver generates appropriate measurement signals which are evaluated by the control electronics  20 . In the initial state in the partial view of  FIG. 7A , i.e. without actuation of the operating portion  12  by the user, the operating portion  12  is situated in its initial position and reflects the radiation R 1  to the receiver  18 . In the case of an action of force F by the user on the operating portion  12 , the operating portion  12  is shifted inwardly and reflects the radiation R 2  to the receiver  18 . A comparison between the two partial illustrations in  FIGS. 7A and 7B  shows that there is a very clear change in the registration location of the reflected radiation R 2 , even in the case of a relatively small travel of the operating portion  12 . This relative change in the registration location is registered by the spatially resolving receiver  18  in such a way that the control electronics  20  can register an actuation of the operating portion  12 . 
         [0065]    Optionally, the rear side of the operating portion  12  may also deviate from the planar form in order to amplify the effect of the change in the registration location. 
         [0066]    Otherwise, the second embodiment variant of  FIGS. 7A and 7B  corresponds to the first embodiment variant described above on the basis of  FIGS. 1A and 1B . 
         [0067]    Furthermore, the two embodiment variants of  FIGS. 1A and 1B  and  FIGS. 7A and 7B  may be combined with one another. Then, the operating portion  12  is both slightly deformed and moved a little in the case of an action of force by a user.