Abstract:
An operating device for an electric appliance has a plurality of display elements, a plurality of operating elements below a translucent operating surface in order to operate by applying a finger and drawing the finger over the operating surface. The operating elements are flat capacitive sensor elements and together with the display elements have common accommodation housings. The sensor elements are placed on top of the accommodation housings and the display elements are arranged in through-holes in the housings. The operating device has at least two accommodation housings that are arranged next to each other.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage application, filed under 35 U.S.C. §371, of International Application PCT/EP2012/055190, filed Mar. 23, 2012, which claims priority to German Application No. 10 2011 006 021.9, filed Mar. 24, 2011, both of which are hereby incorporated by reference in their entirety. 
     TECHNOLOGICAL FIELD 
     The invention relates to an operating device for an electric appliance having a plurality of display elements, a plurality of operating elements, and a translucent or at least partially transparent or light transmitting operating surface, with display elements and operating elements disposed below the surface. 
     BACKGROUND 
     Such operating devices are known from WO 2010/094796 A1, for example. By applying a finger and by drawing an applied finger across, respectively, operation of the electric appliance is achieved. The operating elements detect by well-known ways and means the respective location of the placed-on finger and thus movement thereof. The display elements display a power level set by a finger move, for example. 
     To implement such a convenient and optically very appealing operating device, either an aforementioned touch screen may be employed, which is very expensive, however, and may not in any case be used in a low number of units with unlimited flexibility. As an alternative, individual operating elements and individual display elements may be employed very flexibly, and be attached to corresponding component supports, for example. However, there is an increased effort entailed, and in particular this means high labor input for mounting. 
     SUMMARY 
     The invention is based on the object to provide an above mentioned operating device capable of avoiding the problems of the state of the art, and in particular to provide an efficient and for mass production adapted option, to provide an aforementioned operating device for an electric appliance, in particular a hob. 
     The object is achieved by an operating device. Advantageous as well as preferred embodiments of the invention are the subject matter of the further claims and will be explained in more detail below. The wording of the claims is incorporated into the contents of the description by explicit reference. 
     According to the invention, it is provided that the operating elements are flat capacitive sensor elements and together with the display elements have common accommodation housings. Thus, components adapted to quasi modular assembly are provided which, considered separately, are always constructed in a similar manner, and can then be mounted in arbitrary number and arrangement, as the case may be, for example on a component support. Thereby, consistently similar operating devices that are matched in detail can be constructed quasi schematically. Therein, a sensor element is provided on a top surface of the accommodation housing, namely facing the operating surface and resting against the underside of the operating surface pressed on by means of the accommodation housing. The display elements in turn are disposed in through-holes in the accommodation housings, for example, one or two display elements per through-hole. At least two identical accommodation housings are employed with the operating device and arranged next to each other, advantageously three or even four. They may be similar or identical as to the structure of the accommodation housing and always be implemented according to a similar, repeated pattern, respectively, with display elements and sensor elements. One single difference between the adjacent accommodation housings is advantageously merely in that they somewhat differ in the arrangement of the through-holes in the accommodation housing. 
     The similarity of the accommodation housings is advantageously based on the feature that each of the accommodation housings has an equal number of through-holes that are arranged and structured in similar or corresponding manner. Thus, to particular advantage, there are one, two, or more larger elongated through-holes provided in each case in the center, and adjoining the short outer edges thereof, small exterior through-holes, in particular three or a corresponding number of smaller through-holes. Advantageously, a few closed fields or zones are provided in the center adjacent to the through-holes, however, just as the exterior through-holes, each adjoining a small through-hole. In other words, there are in each case exterior on both sides small through-holes provided, and between every two small through-holes, there is either a large through-hole or a correspondingly large field which advantageously is closed. Advantageously, this is the criterion to measure the similarity; and variance and variation, respectively, are then based on the feature, whether or not with an accommodation housing, there is an open large through-hole disposed between the small through-holes, or a closed field, and how the open large through-holes and the closed fields are distributed, respectively. In the completed arrangement of a plurality of accommodation housings adjacent or adjoining, there is advantageously an alternation of open large through-holes and closed fields in the center, particularly advantageous is that in each case open large through-holes are provided at the ends. 
     The display elements in the through-holes are shielded one from the other by the accommodation housing as such and the walls thereof or the like, respectively, so that the corresponding through-holes, like luminous fields, luminous symbols and the like, are illuminated and thus are visible through the operating surface. In that context, the luminous effect is affected by the shape design of the through-hole, inter alia. Therein, display elements, preferably in the form of LEDs (light-emitting diodes) advantageously project into the through-holes such that outshining from a through-hole sidewards and into an adjacent through-hole, respectively, is prevented. 
     In a first general embodiment of the invention, the sensor elements are separate components and produced separate from the accommodation housings. For example, they can be made of flat material, in particular sheet metal or copper sheet, and be produced by fabricating of recesses and bending and deforming, respectively. One option is cutting from sheet metal and bending, in a manner generally known for such sensor elements. To particular advantage, the sensor elements are placed on a top of the accommodation housing, to be supported thereon, and then pressed against the underside of the operating surface. Fixing of the sensor elements can be achieved either by the pressing on, or in that the sensor elements are at least on one side, preferably on two opposite sides, projecting beyond the accommodation housing with lateral projections. The latter can serve for attachment and/or electric contacting. To that, the lateral projections can be bended twice, and thereby reach down to a bottom of the accommodation housing and up to a component support, respectively, where the accommodation housings are disposed. Projections of a sensor element laterally projecting and resting on the component support, can rest on a contact field, and be fixed by soldering, for example, as an alternative also be fixed by a plug connection and contacted electrically. Therein, the sensor elements may even serve for fixing the accommodation housing as such on the component support. 
     In another embodiment of the invention, it can be provided that one single sensor element is provided per accommodation housing, and one accommodation housing includes or forms but one single sensor element, respectively. Furthermore, it can be provided that the sensor element overlaps or covers a smaller surface area than the top surface of the accommodation housing. Primarily, there should possibly not be zones of the sensor element extending above perforations including display elements therein so that the display function thereof is not impaired. Another option is that radiation from the display elements is passing through cutouts in the sensor element, and the luminous effect is affected by the shape design thereof and the shape design may form a luminous display, respectively. 
     In an embodiment of the invention, it can be provided that the sensor element essentially overlaps and covers the accommodation housing with the exception of two or three sensor element cutouts. In that context, there should, primarily towards the sides, in each case only sensor element cutouts be provided that are limited and bordered, respectively, by small webs. Consequently, this means that towards the sides through-holes of the accommodation housing with display elements inside are provided and constitute a display function. 
     An accommodation housing may have a plurality of through-holes in and between a grid-type frame, respectively, so that an accommodation housing per se is essentially configured in a grid type or frame type or divided into fields. Advantageously, an accommodation housing includes three parallel rows of through-holes in a direction of the housing extension, advantageously in the shorter direction. There are two outer rows to the left and to the right of identical through-holes provided, and particularly preferred each includes but one single display element and is approximately square in shape. Interposed may be a central row of through-holes provided, that have a different design and are considerably larger or wider, respectively. For uniform illumination, there may advantageously be more or two display elements provided, and advantageously have a luminosity corresponding to that of the small through-holes. 
     In another embodiment of the invention, the through-holes including display elements may be provided with light diffusing material and have a diffusor function, respectively. To that end, the display elements may essentially be filled with diffusor material, or in particular include it on the top surface thereof, for example in a kind of disk or filling. 
     In an embodiment of the invention, three adjoining accommodation housings may be provided, each with separate sensor elements mounted above, particularly advantageous one sensor element per accommodation housing. On both ends of the central row, the through-holes are not overlapped by a sensor element, while the two outer sensor elements project beyond them with a sensor element projection in the direction of extension of the central row, and advantageously can rest on the underside of the operating surface. By the quasi alternating arranged zones of surface area of a sensor element and free through-hole, the sensor element function is thus ensured, for example according to the manner of a so-called slider by means of a plurality of capacitive sensor elements along a line. In the intermediate zones without sensor element with a through-hole, display elements are provided which either display the slider for an operator, or else, as will be explained in more detail below, indicate a symbol or a value of a display which has been set using the operating device. 
     This is advantageous to allow that the sensor elements actually cover some of the through-holes of the central row, namely in particular every second through-hole. The through-holes of the two outer rows to the left and to the right of the central row always remain essentially free, so that therein display elements can be arranged in the through-holes. Admittedly, there is no concurrent operating element function available here. The sensor elements extend with small webs between the through-holes of the outer rows outwards for electric contacting and mechanical fixing, respectively. 
     The through-holes of the central row may advantageously be significantly wider than the through-holes of the outer two rows. The difference can amount up to a factor of 2 to 5 fold, advantageously 2 to 3 fold. In the longitudinal direction of the arrangement of the three accommodation housings, that is quasi virtually in the operating direction of the slider, the through-holes in all rows may be equal in length. With such a configuration of the operating device, the elongated central through-holes and the short outer through-holes are capable of representing and reproducing, respectively, seven-segment displays (SSD), in particular with a run function in the operating direction of the slider and in the longitudinal direction of the three adjacent accommodation housings, respectively. 
     In a basically different embodiment of the invention, the accommodation housings are made of electrically conductive material, for example hard or soft synthetic material including corresponding additives. The housings rest with their top against the underside of the operating surface, wherein again a plurality of accommodation housings are adjoining. Each can be electrically separated from another by insulation. The top surfaces of the electrically conductive accommodation housings constitute the above mentioned sensor elements and operating elements, respectively. 
     The above mentioned insulation may, for example, be an insulation layer applied permanently to a housing exterior wall, for example also in the form of an adhesive layer or an adhesive strip. As an alternative, it can be an insulating coating or an insulating layer sprayed on using a multicomponent injection molding procedure. Even in the second general embodiment of the invention an accommodation housing may generally be designed similar to the above description, that is, comprise a plurality of through-holes and thus a grid-type shape or frame-type shape. Again, there may be a plurality, preferably three parallel rows of through-holes provided. With three rows of through-holes, two outer rows have identical through-holes, for example with an approximately square shape. A central row of through-holes is located in between, wherein actually in the respective through-holes at least one display element is disposed. 
     In the above described case, the through-holes of the central row may advantageously be significantly wider than the through-holes of the two outer rows. For example, they may be two-fold to five-fold as wide and include two or three display elements for uniform illumination, wherein preferably the illumination in relation to the surface area is correspondent to that of the smaller through-holes. Advantageously, all the through-holes in the extension direction of the three rows are equal in length. 
     In general, according to the invention the accommodation housings may extend in parallel to the operating surface and be flat. In a plan view, they advantageously exhibit a rectangular shape with a width that is one-and-a-half-fold to three-fold as wide as their length. Therein, the accommodation housings rest against another with their longer sides such that with a plurality of adjoining accommodation housings, there is an arrangement provided which in the direction is in total longer than the width thereof. 
     Advantageously, the accommodation housings are placed on component supports, for example circuit boards. The component supports also bear the display elements and contact them electrically, for example LEDs or SMD-LEDs. Even the sensor elements are led to the component support and electrically contacted thereon. For example, sensor element projections projecting laterally beyond the accommodation housings may be used, as already mentioned above. They can be placed on corresponding contact fields and fixed by soldering, and as an alternative be inserted in holes or in plug sockets. 
     These and further features will become apparent both from the claims and also from the description and the drawings, wherein the individual features can each be implemented as one or more in the form of sub-combinations in an embodiment of the invention and in other fields, and present advantageous embodiments that are patentable per se, and for which protection is claimed herein. The subdivision of the application in individual sections and intermediate headlines does not limit the universality of the statements given thereunder. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Exemplary embodiments of the invention are diagrammatically illustrated in the drawings and will be explained in more detail in the following. In the drawings show: 
         FIG. 1  an oblique view of an operating device with operating elements and display elements on accommodation housings; 
         FIG. 2  a plan view on the operating device of  FIG. 1  with operating elements drawn to the right in the form of flat sensor elements, illustrating the grid-type and field-type division of the operating device and the accommodation housings, respectively; 
         FIG. 3  a section through the operating device of  FIG. 1  in the installed condition in an electric appliance; 
         FIG. 4  an individual central accommodation housing according to the operating device of  FIG. 1  in an oblique view; 
         FIG. 5  the accommodation housing of  FIG. 4  with placed-on central sensor element according to  FIG. 2 ; 
         FIG. 6  an oblique view of the lower sensor element of  FIG. 2 ; 
         FIG. 7  an oblique view similar to  FIG. 5  of the lower accommodation housing with placed-on central sensor element according to  FIG. 6 ; 
         FIG. 8  a variant of the operating device similar to  FIG. 1  with three accommodation housings made of electrically conductive synthetic material and electrically separated by means of insulations; 
         FIG. 9  individual accommodation housings similar to  FIG. 8  made of electrically conductive synthetic foam material that yet have to be electrically insulated one from the other during assembly; and 
         FIG. 10  a procedure of an operation method, wherein a finger is drawn across the operating device and in response thereto the display varies accordingly, as illustrated on the right hand side. 
     
    
    
     DETAILED DESCRIPTION 
     In  FIG. 1 , an operating device  11  according to the invention is illustrated in an oblique view, and composed of or comprising three accommodation housings  12   a ,  12   b , and  12   c . The housings are made of electrically insulating synthetic material and are interconnected to form a structural unit, for example by adhesive bonding in the case of synthetic material components. The parting lines between the individual accommodation housings are illustrated by lateral thick lines. The accommodation housings  12  each have, as will become clearer from the following figures, in particular from  FIG. 8  of a similar configuration, on the left and on the edge, corresponding to the above described front and rear end, in each case small through-holes  14 , designed to be approximately square, namely in each case three through-holes  14  per side of an accommodation housing  12 . Further apertures are provided on the accommodation housings  12  between the through-holes  14  and a central zone. With the accommodation housing  12   b , this is a central elongated through-hole  16 . The hole is located between the two central through-holes  14 , while the accommodation housing  12   b  has a solid zone  15  between the other through-holes  14 . 
     The accommodation housings  12   a  and  12   c  each do not have elongated through-holes  16  between the central through-holes  14 , but solid zones  15 . However, between the upper small through-holes  14  and the lower small through-holes  14 , there are two elongated through-holes  16  provided, which are two-times to three-times as long as the small through-holes  14  and have the same width. 
     In the plan view of  FIG. 2 , on the left, there is a field-type or grid-type division of the accommodation housings  12  clearly visible. Furthermore, LEDs  18  are symbolized therein and serve as display elements to implement the display of the operating device. In each small through-hole  14 , there is one LED  18  disposed, in the elongated through-holes  16  are disposed in each case two LEDs  18 . The LEDs allow uniform illumination so that essentially rectangular illumination fields are visible to the top. 
     In  FIG. 2  the respective sensor elements  20   a - c  are illustrated drawn to the right adjacent to the accommodation housings  12   a - c  in a plan view, the same as those included in  FIG. 1 . An upper sensor element  20   a  is made of thin sheet metal, copper sheet, for example, the same as the other sensor elements  20   b  and  20   c . It has two small perforations  21  corresponding to the above sensor element cutouts and which later will be located above the small through-holes  14 . Furthermore, it has an elongated perforation  22  in the central zone, located above an elongated through-hole  16 , as apparent from  FIG. 1 . As a result, the sensor element  20  essentially forms two sensor areas  23  electrically connected to another by production in one piece. The narrow zones around the small perforations  21  serve merely for electrical contacting to the side, what will be described in more detail below. Beyond the small perforations  21 , the sensor element  20   a  has in each case one retaining foot  25 , bended downwards according to  FIG. 1 , and serving both for electrical contact and possibly for fixation, as will be explained in more detail in the following. 
     The sensor element  20   c  is designed similar to the sensor element  20   a , but actually turned downwards by 180° in the plane of projection. 
     Another sensor element  20   b  has a somewhat different design and includes only one single elongated perforation  22 ′ which was produced quasi in that the elongated perforation  22  is inserted exactly between the two small perforations  21  in the sensor element  20   a . The upper sensor area  23  instead is transferred to the lower side of the elongated perforation  22 ′ so that a configuration in longitudinal symmetry is obtained. This means that the elongated perforation  22 ′ is continuously extended over small through-holes  14  arranged in a row with an elongated through-hole  16  in between, and thus exposes the four LEDs  18  below arranged in a row. With the sensor element  20   b  as well, there are retaining feet  25  provided exterior to the perforation  22 ′. 
     A combined consideration of  FIG. 1  and  FIG. 2  on the left reveals also that the operating device  11  according to the invention allows providing a kind of matrix display similar to a seven-segment display, but with significantly finer subdivision. Namely, there are  23  segments present in the form of through-holes  14  and  16  including a total of  28  LEDs  18 , and each through-hole  14  and  16  and each field, respectively, can be controlled autonomously. Thereby, figures or characters can be displayed, not only according to a seven-segment display, as will be explained in more detail below, but there is even a kind of running display or ticker writing feasible, as will be explained in more detail below. 
     In  FIG. 3  a section through an operating device  11  according to the invention in an electric appliance is shown, for example using a glass ceramic plate  10  as a hob and operator control panel. Therein, on a circuit board  27  the LEDs  18  are disposed in the small through-holes  14  and the elongated through-hole  16 , respectively. Indeed, a sensor element  20  is extended over the corresponding accommodation housing  12 , however, directly above the through-holes  14  and  16 , respectively, and thus also the LEDs  18  with cutouts, for example the elongated perforation  22 ′ with sensor element  20   b . Thus, the sensor element  20  will not interfere with the upward illuminating effect of the LEDs  18 , or merely inessentially at the edge. 
     The arrangement of  FIG. 3  may be configured such that the operating device  11  with the sensor element  20   b  rests on the underside of the glass ceramic plate  10 . The accommodation housings  12  may either be adhesively bonded to the circuit board  27 , or attached by other retaining means. Another option is, to secure them by means of the sensor elements  20 . Namely, a retaining foot  25  of the sensor element  20   b  is provided for that purpose on the top of the circuit board  27 , and may there be fixed by soldering, for example on a contact field, for electric contacting and mechanical fixation. 
     The illustration of  FIG. 1  also demonstrates that the operating device  11  has six sensor areas  23  in a line, that is, two sensor areas  23  per accommodation housing  12 . Adjacent sensor areas have a free surface area there between, presenting approximately the same size, and with an elongated through-hole  16  located below it. Each of the sensor areas  23  are like one even in relation to electric characteristics and in each case constitute a capacitive sensor element, as apparent from  FIG. 3 . 
     In  FIG. 4 , an individual accommodation housing  12   b  is illustrated, to further demonstrate the configuration including small through-holes  14  and elongated through-holes  16 . In  FIG. 5 , the accommodation housing  12   b  of  FIG. 1  is illustrated with a sensor element  20   b  placed-on. A direct comparison reveals that the sensor areas  23  of the sensor element  20   b  are located above the solid zones  15  of the accommodation housing  12   b  above and below the elongated through-holes  16 . The central small through-holes  14  are also open to the top, due to the length of the elongated perforation  22 ′ in the sensor element  20   b . The small through-holes  14  in the corners are neither covered nor bordered by the sensor element  20   b , anyway. 
     In  FIG. 6 , the sensor element  20   e  is again illustrated in an oblique view, as indicated above. It is apparent here as well that the sensor element  20   c  is produced by cutting and deforming and bending, respectively of one single sheet metal component, wherein mainly the two sensor areas  23  remain, and then act as a capacitive sensor element having two distributed areas. Equally, the small through-holes  14  and the elongated through-hole  16  are identified that allow radiation of the LEDs  18  to the top. 
       FIG. 7  illustrates how the sensor element  20   c  is placed on an accommodation housing  12   c . As mentioned above, the upper sensor area  23  is located above the solid zone of the accommodation housing  12   c  which according to  FIG. 2  does not include an LED anyway. The lower elongated through-hole  16  is located below the elongated perforation  22  to allow radiation passing, and the central small through-holes  14  are located similarly below the small perforations  21  to allow radiation passing. The lower sensor area  23  projects downwards beyond the accommodation housing  12   c , see also  FIG. 1 . 
     In  FIG. 8 , an alternative operating device  111  is illustrated and as well comprises three accommodation housings  112   a ,  112   b , and  112   c . The housings are in relation to geometry designed similar to the illustrations in  FIGS. 1 ,  2 ,  4 ,  5 , and  7 . However, a difference is in that they are made of relatively hard electrically conductive synthetic material, and actually are also interconnected and adhesively bonded, respectively. Optionally, the electric conductivity may also be obtained by a corresponding electrically conductive coating, covering advantageously at least the top surfaces, and with particular advantage reaches downwards for electrical contacting. Interposed between the individual accommodation housings  112   a  to  112   c  are, however, two insulations  129 , for example also as an insulating double-faced adhesive tape or adhesive material. Since the accommodation housings  112   a - c  per se are electrically conductive, they equally constitute capacitive sensor elements, in particular with the solid zones  115 , which then would directly rest on the underside of the glass ceramic plate, according to  FIG. 3 , what is well-known to be decisive for the function of a capacitive sensor element for a contact switch, see EP 859 467 A, for example. However, since there are herein no projecting sensor areas according to  FIG. 1  or  7  illustrated, the operating device  111  of  FIG. 8  has only four sensor areas  123  that actually are constituted by the solid zones  115 . Optionally however, there may be additional wing-type prolongations corresponding to the outmost sensor areas  23  according to  FIG. 1  provided on the accommodation housings  112   a  and  c.    
       FIG. 8  also shows, like for instance according to the other figures, that two different types of accommodation housings have to be provided, even without separate sensor elements made of sheet metal or the like. 
     In  FIG. 9  another example of the accommodation housings  212   a  and  212   b  is illustrated. The housings are generally similar to those of  FIG. 8 , however, they are not made of hard synthetic material, but of soft and elastic, respectively, synthetic material, for example foamed synthetic material. In the figures this is illustrated in that the corners and edges are somewhat more rounded. In the other respects, the three accommodation housings  212   a  and  212   b  may be configured and be assembled according to  FIG. 8 . 
     In  FIG. 10  is illustrated, how an operating device  11  according to  FIG. 1  can be operated in the installed condition below a glass ceramic plate  10  according to  FIG. 3  or the like. A hand  31  and a finger  32  touch the operating device  11  above the display by the LED  18 , which actually is setting a “3”, as illustrated on the right side on top. The “3” is formed by short and elongated illuminated symbols corresponding to the small through-holes  14  and elongated through-holes  16 , wherein the LEDs  18  are located. It is apparent that on the right side, there are five small through-holes  14  superimposed and illuminated, that is, even more through-holes or illuminated symbols may be generated both upwards and downwards. A circle shown in dashed lines indicates the location where the finger  32  is placed-on and moves downwards according to the thin arrow shown on the left side. The result is a movement of the numeral “3” according to the thick arrow shown on the right side. 
     On the left side of the median illustration is shown, how the finger  32  is moved downwards in a drawing or brushing motion and thereby quasi the “3” moves downwards, wherein concurrently from above a next numeral, namely the “4”, is entering the image, what is also indicated by a thick arrow on the right side. There can also a so-called slider operator control movement of the finger  32  be obtained by the sensor areas  23  of the sensor elements  20  with six of them disposed in a row, all of them arranged and configured actually like a well-known slider as mentioned above. Furthermore, according to the drawing operator control movement, even the indicated numeral can be moved by an operating device including a display in a simple configuration. 
     In  FIG. 10  on the left side bottom is illustrated, how the finger  32  has reached the bottom end using the operating device  11 . In the functional illustration adjoining to the right side, the feature is illustrated once again. Furthermore, it is apparent that the previous numeral “3” has almost completely disappeared from the field of view, and the display has disappeared downwards, respectively, while the next numeral “4” has appeared almost completely. 
     With the method of operation it may be provided that the next numeral “4” enters automatically in a central location on the display, even if the finger movement does not reach as far as needed. The “4” is then both displayed and supplied via the operating device  11  to a control unit for a corresponding functional unit of the electric appliance, a cooking zone of an electric hob, for example.