CONTROL UNIT FOR A HOUSEHOLD APPLIANCE

Description

[0001] The invention relates to a control unit for a household appliance with a touch-sensitive unit and an LED unit positioned behind it, wherein the touch-sensitive unit is formed with a diffuser film, the upper side of which facing the operator has at least one character layer and the lower side of which faces away from it has at least one functional layer.

[0002] Numerous control units for household appliances are known from the prior art. In the simplest case, a household appliance is operated using push buttons or rotary switches, the position of which is indicated by markings on a control panel. The use of unilluminated membrane keys, for example on microwave ovens, is also known. Furthermore, touch-sensitive sensor buttons grouped around a small LCD display are known, with their current function indicated to the user by a symbol.

[0003] Furthermore, backlit touchscreens are now widely used in household appliances, offering a particularly user-friendly experience. Touchscreens are also easy to clean thanks to their smooth, continuous surface and are more hygienic than conventional controls. However, a disadvantage is that adapting the control symbols for backlit touchscreens to different requirements or device variations in mass production is comparatively complex and costly.

[0004] WO 2015 / 090361 A1 discloses the preamble of claim 1. US 2010 / 142211 A1, DE 10 2015 013054 A1, DE 20 2014 101897 U1, EP 1 903 284 A1, DE 10 2019 104435 A1 and DE 10 2016 212995 A1 are further relevant parts of the prior art.

[0005] One object of the invention is therefore to provide a touch-sensitive and backlit control unit whose symbolism has a large and easily changeable variability.

[0006] The problem mentioned at the outset is solved according to claim 1 in that the at least one character layer has at least one character produced by means of laser radiation which is at least partially transparent to light from the LED unit, wherein the character layer is opaque to light from the LED unit outside of the at least one character.

[0007] Consequently, the characters within the character layer are completely independent and can therefore be produced after the manufacturing process of the touch-sensitive unit and the associated lighting unit, as well as the connection to the complete control unit, is complete. This allows for a wide variety of control unit models for different types of household appliances to be realized with minimal effort. The characters can be created, for example, using a laser ablation process on a previously applied, opaque layer, coating, film, or similar material on the diffuser film. Furthermore, deep laser engraving of the opaque layer or cutting out the desired character contour from the opaque layer using laser radiation is also possible.The production of the at least one functional layer, which contains the conductive traces, the capacitive touch electrodes, and an electrical interface, can be achieved, for example, by cutting out a corresponding conductive trace from a laminated copper foil using laser radiation of a suitable wavelength and intensity or power. The functional layer with the conductive trace necessary for touch functionality can be formed using a conventional screen printing process. The functional layer is preferably printed onto the side of the diffuser film facing away from the user. Alternatively, the functional layer can also be implemented with a touch-sensitive film designed as a separate component. This touch-sensitive film can be bonded to the side of the diffuser film facing away from the user in a suitable manner, for example, by gluing or welding.Furthermore, creating the characters within the character layer using laser radiation allows for particularly high contour sharpness and dimensional accuracy of the characters, while simultaneously enabling virtually unlimited variability. The laser radiation can be generated with a gas or solid-state laser of sufficiently high power at a wavelength suitable for cutting and deep engraving. The term "LED" (so-called ". L light E mitting D The term "iode") is used synonymously with "light-emitting diode" in the context of this description.

[0008] According to the invention, a circuit board of the LED unit has at least one light-emitting diode for the preferably selective backlighting of at least one associated character of the character layer. Due to the backlighting of the characters of the character layer, particularly good readability is ensured. If necessary, by activating certain LEDs of the LED unit, the respective associated characters can be selectively illuminated or periodically flashed, for example, to transmit targeted operating instructions to an operator of the household appliance.

[0009] According to the invention, the circuit board of the LED unit has at least one numeric and / or alphanumeric display for preferably selectively backlighting an associated character of the character layer. This enables more extensive user interaction. The at least one display can, for example, be in the form of an LED 7-segment display, an LED 5 x 7 dot matrix display, etc.

[0010] According to the invention, the at least one functional layer has a plurality of capacitive touch electrodes configured to generate an evaluable electrical signal in the event of spatial proximity of a user's finger. This signal can be derived via a first electrical interface of the at least one functional layer. As a result, contactless, mechanically robust, and intuitive control of the household appliance's functions via the control unit is ensured. Furthermore, the control unit is insensitive to moisture and easy to clean by wiping, thus ensuring a high standard of hygiene.

[0011] In a further embodiment, the LED unit's circuit board has a second electrical interface that is connected to the first electrical interface of the touch-sensitive unit and / or to at least one electronic control unit associated with the circuit board and / or an electronic control and / or regulating unit of the household appliance. This ensures seamless electrical integration of the operating unit into the household appliance.

[0012] Preferably, the electronic control unit is configured at least to evaluate the electrical signals from the capacitive touch electrodes. As a result, the comparatively weak capacitive signals from the touch electrodes can be amplified, and the touch-sensitive buttons formed by the touch electrodes can be reliably selected.

[0013] According to the invention, the at least one functional layer is provided on its underside with a protective layer, which in turn is provided on its underside, at least in some areas, with an adhesive layer. Due to the adhesive layer, a robust and easily manufactured mechanical connection is provided between the touch-sensitive unit and the LED unit to create the control unit.

[0014] According to the invention, the adhesive layer has a non-adhesive peelable layer on its underside.

[0015] This makes handling the touch-sensitive unit easier until the final assembly of the control unit.

[0016] According to the invention, each light-emitting diode (LED) and each numeric or alphanumeric display of the LED unit is assigned a light channel as part of a light guide. This prevents optical crosstalk between light signals of spatially closely adjacent LEDs or alphanumeric LED displays, thus enabling particularly sharp backlighting of the characters on the display layer. The light channels can have an inner surface that is at least partially mirrored.

[0017] According to the invention, the light guide outside the light shafts has an opaque blocking layer facing the touch-sensitive unit. As a result, light reflections that would otherwise occur between boundary layers in the stack structure are avoided. The blocking layer is arranged on the upper side of the light guide, below mask-like recesses or openings in the light shafts, and can, for example, be formed by an adhered, thin black film.

[0018] In an advantageous technical development, the character layer is provided with a translucent cover. This prevents damage to the character layer from external mechanical influences during operation of the household appliance.

[0019] Preferably, the touch-sensitive unit comprises a 2D sensor with a touch-sensitive area such that the at least one character of the character layer can be formed largely freely within the touch-sensitive area. This allows for particularly high flexibility with regard to the two-dimensional positioning of the characters of the character layer and the functionalities assigned to them. For this purpose, the at least one functional layer can have a plurality of capacitive touch electrodes, which can be arranged, for example, in the form of a regular, sufficiently fine orthogonal and two-dimensional dot grid.

[0020] A preferred embodiment of the invention is explained in more detail below with reference to schematic figures. These show... Figure 1 shows a highly schematic cross-section of an operating unit according to the invention in a partially assembled state, Figure 2 shows a top view of the operating unit of Figure 1 For a household appliance, Figure 3 shows a schematic, perspective view of the touch-sensitive unit of the control unit according to the Figure 1 , 2 , and Figure 4 the touch-sensitive unit of Fig. 3 with an exemplary symbol formed using laser radiation from a suitable laser.

[0021] The Figure 1 shows a highly schematic cross-section of an operating unit according to the invention in a partially assembled state.

[0022] The control unit 100 for a household appliance (not shown) comprises, among other things, a touch-sensitive unit 106 and an LED unit 112 positioned behind it. The touch-sensitive unit 106 is formed with a diffuser film 116 and serves to even out the backlighting from the LED unit 112. A top surface 122 of the diffuser film 116 has at least one character layer 130, at least partially formed, facing the eye 124 of a human operator of the household appliance (not shown). An electrical functional layer 148 is formed on a lower surface 142 of the diffuser film 116 facing away from the operator. The at least one character layer 130 shows, by way of example, two characters 154 and 156 generated by laser radiation (not shown).The characters 154 and 156 of the character layer 130 are each at least partially transparent to visible light 164 and 166 emitted by, for example, two light-emitting diodes 160 and 162 of the LED unit 112. Preferably, the characters 154 and 156 completely penetrate the character layer 130. Outside of the characters 154 and 156, the character layer 130 is essentially opaque, acting like a mask. The characters 154 and 156 can be created, for example, by ablation using laser radiation of an opaque layer or film previously applied to the diffuser film as the character layer 130. Alternatively, deep laser engraving of the opaque layer serving as the character layer 130 or complete cutting out of the character contour using laser radiation of sufficiently high intensity from the character layer 130 is possible.

[0023] The diffuser film 116 preferably has a stiffening 172 in the area of ​​its upper surface 122. Preferably, a first electrical interface 178 is formed in the area of ​​a lower surface 174 of the functional layer 148. The stiffening 172 is vertically separated from the electrical interface 178 by the diffuser film 116 and the functional layer 148, but these are positioned essentially congruently to each other in order to ensure the most reliable, electrically and mechanically robust contact possible with the touch-sensitive unit 106. The character layer 130 and the stiffening 172 are preferably provided with a translucent cover 184 over their entire upper surface, so that mechanical damage to the character layer 130 is prevented. The cover 184 can be designed to be selectively transparent to the light 164, 166 emitted by the light-emitting diodes 160, 162 in order to reduce the influence of ambient light.

[0024] The underside 174 of the functional layer 148 is preferably protected, except for the first electrical interface 178, by a protective layer 188 against harmful, in particular corrosive, environmental influences and moisture. The protective layer 188 is at least partially provided with an adhesive layer 190, which in turn is at least partially covered with a non-adhesive, film-like release layer 192 to facilitate handling of the touch-sensitive unit 106 before its final connection with the LED unit 112. Both the functional layer 148 and the protective layer 188, as well as the adhesive layer 190, are sufficiently transparent to the light 164, 166 emitted by the light-emitting diodes 160, 162.

[0025] The functional layer 148 here merely includes two capacitive touch electrodes 194, 196, which are designed to generate an electrical signal when a finger of the human operator approaches, which can be derived for further processing by means of the first electrical interface 178 of the functional layer 148.

[0026] The further processing of the electrical signals generated by the capacitive touch electrodes 194, 196 can be carried out, for example, using an electronic control unit 200 associated with the LED unit 112. The capacitive touch electrodes 194, 196 of the functional layer 148, as well as electrical conductors (not shown) for their electrical connection to the first electrical interface 178, can be formed, for example, using a screen printing process. Alternatively or additionally, the functional layer 148 can be laminated, at least in some areas, with a copper foil (not shown) in which the capacitive touch electrodes 194, 196, the conductors, and the first electrical interface 178 are formed, for example, by chemical etching and / or by laser cutting.

[0027] The LED unit 112, shown here only as an example, has a printed circuit board 206 (PCB). The PCB 206 serves, among other things, for the electrical interconnection of the LEDs 160 and 162, the electronic control unit 200, and a second electrical interface 210, using electrical traces not shown. The PCB 206 can also feature numerical and / or alphanumeric displays (not shown) to enable more complex user interaction. For example, a numerical display can be implemented using a 7-segment LED display, and an alphanumeric display can be implemented using a 5 x 7 dot matrix LED display. Furthermore, 17-segment LED displays can be used for limited alphanumeric display.The LEDs 160 and 162 are preferably positioned directly below their respective characters 154 and 156 of the character layer 130, so that the characters 154 and 156 can be illuminated individually if necessary. The same applies to optionally provided alphanumeric displays of the LED unit 112.

[0028] The second electrical interface 210 of the circuit board 206 of the LED unit 112 can, for example, be electrically connected to the first electrical interface 178 of the touch-sensitive unit 106 and / or to the electronic control unit 200 and / or to a higher-level electronic control and / or regulating unit of the household appliance (not shown).

[0029] Each of the LEDs 160, 162 is assigned a light channel 216, 218 to prevent optical crosstalk between the LEDs 160, 162. This ensures that when the first character 154 is illuminated by activating LED 160, the second character 156 is not passively illuminated when LED 162 is inactive. The same applies to the optional alphanumeric LED display of the LED unit 112. The two tube-like light channels 216, 218 together form a light guide 220 for the LED unit 112. Furthermore, the light guide 220 is covered outside the light channels 216, 218 with an opaque or light-absorbing blocking layer 224 to prevent unwanted light reflections. For this purpose, the blocking layer 224 is located on a top surface 226 of the light guide under a mask-like recess orThe light shafts 216, 218 are secured, in particular by gluing or welding. In the partially assembled state of the control unit 100 illustrated here, there is still a small gap A between the touch-sensitive unit 106 and the LED unit 112. To complete the assembly of the control unit 100, the release layer 192 is removed and the touch-sensitive unit 106 is joined to the blocking layer 224 of the LED unit 112 by gluing, welding, etc., using the adhesive layer 190, so that the gap A becomes zero.

[0030] By individually addressing or switching on the LEDs 160, 162 with the aid of the electronic control unit 200, the respective assigned characters 154, 156 can be illuminated, for example, continuously or periodically. This allows, for example, an intuitively perceptible operating instruction to be given to the operator, dependent on the current status of the household appliance, to activate the touch electrodes 194, 196 assigned to the flashing character 154, 156.

[0031] For example, in the case of a washing machine, the operator can be actively prompted to preselect a suitable wash program, wash temperature, and / or spin speed and start the washing machine by activating the backlit characters 154 and 156. Furthermore, a warning message can be displayed, for example, to enable the water supply to the washing machine in order to start the wash cycle. The LEDs 160 and 162 of the LED unit 112 can be at least partially permanently illuminated to provide static backlighting for the touch-sensitive unit 106.

[0032] The Figure 2 shows a top view of the control unit of Figure 1 for a household appliance. The control unit 100 features the touch-sensitive unit 106, which is concealed here. Figure 1 with the touch electrodes for activation by the user's finger approaching them.

[0033] The control unit 100 features a variety of characters, with character 250 being designed as symbols or pictograms, and further characters 252 being designed as letters or minus signs, plus signs, or periods. Character 254 is designed as 7-segment digits for displaying Arabic numerals, and character 256 is designed as a 5 x 7 dot matrix for visualizing any alphanumeric characters such as Latin letters and Arabic numerals. In addition, a variety of rectangular characters 258 are provided, which can serve, for example, as bar graphs, optical dividers, or for displaying visual operator instructions.

[0034] All characters 250 to 258 are formed within the character layer of the touch-sensitive unit 106 by means of laser radiation, for example by cutting or separating, laser engraving, or the like, and are transparent to the light emitted by the LEDs, the optional 7-segment LED displays, or the optional 5 x 7 dot matrix LED displays. If necessary, the character layer can also have printed characters, at least additionally, which can be done, for example, by means of known screen printing processes.

[0035] The touch-sensitive unit 106 can optionally be configured, at least partially, as a 2D sensor by creating a touch-sensitive area 270. This allows the characters 250 to 258 to be formed practically freely, i.e., arbitrarily, within the character layer or the touch-sensitive area 270 using laser radiation. The touch-sensitive 2D sensor can, for example, be implemented with a plurality of capacitive sensing electrodes arranged in a grid on the functional layer of the touch-sensitive unit 106. The grid in which the sensing electrodes of the functional layer are positioned is preferably orthogonal, uniformly square, and sufficiently fine with respect to the physical size of the characters.

[0036] The Figure 3 shows a schematic, perspective view of the touch-sensitive unit of the control unit according to the Figure 1 , 2The touch-sensitive unit 106 comprises the diffuser film 116 with the user-facing character layer 130 and the downward-facing functional layer 148. The functional layer 148 is protected on its underside by the protective layer 188 against harmful environmental influences such as corrosion, moisture, and mechanical damage. The adhesive layer 190 extends at least partially beneath the protective layer 188 and is provided with the non-adherent, film-like release layer 192 to improve handling during the assembly process of the operating unit. Above a projection 300 of the diffuser film 116, the character layer 130 is omitted, and the stiffening element 172 is applied at a distance from the character layer 130, preferably with a gap 302 created. Below the extension 300 of the diffuser foil 116, and essentially congruent with it, runs the functional layer 148.The first electrical interface 178 is formed on the underside 174 of the functional layer 148, which is at least slightly overlapped by the protective layer 188 of the functional layer 148.

[0037] The character layer 130 of the diffuser film 116 does not yet show any characters formed by means of laser radiation from a suitable laser.

[0038] The Figure 4 shows the touch-sensitive unit of Fig. 3with an exemplary character formed by means of laser radiation from a suitable laser. The layer structure (so-called "stack") of the touch-sensitive unit 106 comprises, starting from the user-facing character layer 130, the diffuser film 116, the functional layer 148, the protective layer 188, the adhesive layer 190, and the peel-off layer 192. The stiffener 172 is arranged above the extension 300 of the diffuser film 116. The first electrical interface 178 is positioned below an extension 304 of the functional layer 148, essentially congruent with the stiffener 172.

[0039] In contrast to the representation of Figure 3As an example, a character 310, representing the Latin capital letter "H", is introduced into the character layer 130 using laser radiation 312 from a suitable laser 320. The character 310, as an example, completely penetrates a material thickness M of the character layer 130 and thus forms a character recess 322 that is transparent to the light from the LED unit (not shown) without loss.

[0040] Due to the formation of the characters on the marking layer 130 using the laser 320, a high degree of graphic variability is achieved, allowing for easy, flexible, and rapid adaptation to the requirements of different types and / or variants of household appliances. The use of laser radiation 312 from a laser marking device (not shown) ensures extremely sharp contours, highly dimensionally accurate, and reliably reproducible geometric design of the individual characters. The intensity of the laser radiation 312, or the power of the laser 320, is precisely measured to prevent damage to the underlying diffuser film 116 during the character formation process on the marking layer 130.

[0041] Furthermore, the characters of the character layer 130 can be easily produced using the laser 320 after completion of the assembly of the touch-sensitive unit and the LED unit to create the operating unit - i.e. immediately before its installation in a household appliance.

[0042] The invention relates to an operating unit 100 for a household appliance with a touch-sensitive unit 106 and an LED unit 112 positioned behind it, wherein the touch-sensitive unit 106 is formed with a diffuser film 116, the upper surface 122 of which facing the operator has at least one character layer 130 and the lower surface 142 of which faces away from it has at least one functional layer 148. According to the invention, the at least one character layer 130 has at least one character 154, 156, 250, 252, 254, 256, 258 produced by means of laser radiation 312, which is at least partially transparent to light from the LED unit 112, wherein the character layer 130 is opaque to light 164, 166 from the LED unit 112 outside of the at least one character 154, 156, 250, 252, 254, 256, 258.This gives the control unit 100 a high degree of variability and allows it to be easily adapted to different types and / or kinds of household appliances with minimal effort. Reference symbol list

[0043] 100 Operating unit 106 Touch-sensitive unit 112 LED unit 116 Diffuser film 122 Top (diffuser film) 124 Eye (human operator) 130 Character layer 142 Bottom (diffuser film) 148 Functional layer 154 Character 156 Character 160 Light-emitting diode 162 Light-emitting diode 164 Light 166 Light 172 Stiffener 174 Bottom (functional layer) 178 First electrical interface 184 Cover 188 Protective layer 190 Adhesive layer 192 Peel-off layer 194 Touch electrode 196 Touch electrode 200 Electronic control unit 206 Circuit board 210 Second electrical interface 216 Light shaft 218 Light shaft 220 Light guide 224 Blocking layer 226 Top (Lighting guidance) 250 Character (symbol, pictogram) 252 Character (letters) 254 Character (7-segment digit) 256 Character (dot matrix) 258 Character (rectangles) 270 Touch-sensitive area (2D sensor) 300 Extension (diffuser film) 302 Gap 304 Extension (functional layer) 310 Character recess 312 Laser radiation 320 Laser 322 Recess (character) ASpacing MMaterial thickness (drawing layer)

Claims

1. Operating unit (100) for a household appliance having a touch-sensitive unit (106) and an LED unit (112) positioned to the rear of the same, wherein the touch-sensitive unit (106) is formed with a diffusor film (116), the top side (122) of which facing an operator has at least one layer of symbols (130) and the bottom side (142) of which facing away herefrom has at least one functional layer (148), wherein the at least one functional layer (148) has a plurality of capacitive working electrodes (194, 196), which are embodied in each case to generate an evaluable electrical signal if a finger of an operator were to approach spatially, said electrical signal being derivable by means of a first electrical interface (178) of the at least one functional layer (148), wherein a conductor board (206) of the LED unit (112) has at least one light-emitting diode (160, 162) for the preferably selective backlighting of at least one assigned symbol (154, 156, 250, 252, 254, 256, 258) of the layer of symbols (130), and wherein the conductor board (206) of the LED unit (112) has at least one numerical and / or alphanumerical display for the preferably selective backlighting of an assigned symbol (154, 156, 250, 252, 254, 256, 258) of the layer of symbols (130), wherein the at least one layer of symbols (130) has at least one symbol (154, 156, 250, 252, 254, 256, 258) which is produced by means of laser radiation (312) and is at least partially permeable to light from the LED unit (112), wherein the layer of symbols (130) outside of the at least one symbol (154, 156, 250, 252, 254, 256, 258) is impermeable to light (164, 166) of the LED unit (112), wherein each light-emitting diode (160, 162) and each numerical or alphanumerical display of the LED unit (112) is assigned a funnel (216, 218) as part of a light guide (220), and wherein the light guide (220) outside of the funnels (216, 218) has a light-impermeable blocking layer (224) facing the touch-sensitive unit (106), characterised in that the at least one functional layer (148) is provided on the underside with a protective layer (188) which is provided for its part at least in sections on the underside with an adhesive layer (190), wherein the adhesive layer (190) has a non-adhesive peel coat (192) on the underside.

2. Operating unit (100) according to claim 1, characterised in that the conductor board (206) of the LED unit (112) has a second electrical interface (210), which is connected to the first electrical interface (178) of the touch-sensitive unit (106) and / or with at least one electronic control unit (200) assigned to the conductor board (206) and / or an electronic control and / or regulating unit of the household appliance.

3. Operating unit (100) according to claim 1, characterised in that the electronic control unit (200) is at least embodied to evaluate the electrical signals of the capacitive working electrodes (194, 196).

4. Operating unit (100) according to one of claims 1 to 3, characterised in that the layer of symbols (130) has a light-permeable cover (184).

5. Operating unit (100) according to claim 1, characterised in that the touch-sensitive unit (106) has a 2D sensor by creating a touch-sensitive region (270), such that the at least one symbol (154, 156, 250, 252, 254, 256, 258) of the layer of symbols (130) can be formed largely freely within the touch-sensitive region (270).