Electrical appliance with a display device

Abstract

Electrical appliance (31) with a display device (11), wherein: - the electrical appliance (31) has a display panel (28) under which the display device (11) is arranged, - the display device (11) is pressed against the underside (29) of the display bezel (28) with a cover (22) and thus rests against the underside (29), wherein the display device (11) comprises: - a flat component support (13), - at least two cuboid or block-shaped display elements (15) on the component carrier (13), wherein the display elements (15) have display top surfaces (16) that point away from the component carrier (13) and that lie in a common plane, - Light sources (14) in the display elements (15), - a holding device (19) for the component carrier (13), where - the display device (11) has at least the cover (22) over the display elements (15) made of translucent and flexible flat material, - the cover (22) rests on the top of the display (16), - the cover (22) is attached to the display device (11) as part of the same, - the cover (22) and the display device (11) form a single unit, characterized in that the display tops (16) are provided with an opaque coating which has at least one cutout (17) without coating per display element (15), wherein the cutout (17) is produced by removing the coating by means of a laser.

Description

SCOPE OF APPLICATION AND STATE OF THE ART

[0001] The invention relates to an electrical appliance, in particular a cooktop, equipped with a display device, wherein the display device may also have an operating function.

[0002] From DE 102009036161 A1, it is known to arrange a display device with display elements on a component carrier under the cooktop surface of a hob. These are, for example, so-called seven-segment displays. They shine through the cooktop surface, which forms a display panel, and are easily visible. To achieve the most uniform illumination possible, it is necessary to maintain as close to the same distance as possible between all display elements of a display device and the underside of the cooktop surface. Since it is often not easy to adjust this distance precisely, the display elements are pressed against the underside of the cooktop surface with their upper surfaces. Thus, the upper surfaces of all display elements are, so to speak, at the same height and level with the underside of the cooktop surface, although they may be pressed against it.

[0003] From DE 19724992 A1, it is known to provide a special display device under a cooktop with a cooktop plate. A transparent silicone layer is provided between the display device and the underside of the cooktop plate, which has wave-shaped surface irregularities.

[0004] From US patent 2012 / 0138042 A1, it is known to arrange a display screen under a cooktop surface of a hob, which is mounted on a display carrier. The display carrier, in turn, sits in a silicone frame, which elastically presses it against the underside of the cooktop surface. A number of control elements are provided on both sides of the display.

[0005] German patent DE 196 33 706 C2 discloses a cooktop with a glass-ceramic surface, in which the underside of the glass-ceramic surface has a textured surface with raised bumps over a large portion of its area. In a peripheral area where capacitive sensor switches for a control device are provided, this textured surface is absent. Furthermore, the patent describes a method for applying silicone to the underside of the glass-ceramic surface to effectively level out the textured surface and create a smooth surface.

[0006] From DE 10 2010 006 777 A1, a cooktop with a glass-ceramic cooktop surface and a control unit arranged beneath it is known. This control unit has combined display and operating elements, which may be made of electrically conductive material. Furthermore, the material may be translucent and elastic. This ensures a good and complete fit against the underside of the cooktop surface.

[0007] From DE 44 24 847 A1, another control device for a cooktop with a glass-ceramic cooktop surface is known, in which the underside of the glass-ceramic surface also has a textured surface. A translucent material is applied to this underside as an immersion layer. This layer is intended both to compensate for the textured surface and to enable the adhesion of a display device with light elements by means of a surrounding frame. Here, too, this compensating layer is applied to the underside of the cooktop surface, initially separately from the control device. TASK AND SOLUTION

[0008] The invention is based on the objective of creating an electrical device with a display unit as mentioned above, with which problems of the prior art can be solved and it is particularly possible to achieve a good display and at the same time to ensure a stable function of the display unit, especially to avoid damage to the display elements.

[0009] This problem is solved by an electrical device with the features of claim 1. Advantageous and preferred embodiments of the invention are the subject of further claims and are explained in more detail below. Some of the features mentioned are described only for the display device or only for the electrical device. However, they are intended to apply to the electrical device regardless. The wording of the claims is made explicit by reference to the content of the description.

[0010] The display device is designed to have a flat component carrier and a mounting device for this carrier. This mounting device is intended to allow the component carrier to be installed in an electrical device or attached to it as a display, thus securing the display device within or on the device. Furthermore, at least two cuboid or block-shaped display elements are provided on the component carrier. It is advantageous for several, especially most or even all, of the display elements on the component carrier or on a display device to be largely identical in design. The display elements have display surfaces that face away from the component carrier or upwards, and in particular towards a future display panel. These display surfaces are therefore located on top, and, most importantly, the display surfaces of a display device or component carrier lie in a common plane.Light sources, preferably LEDs, are provided in or below the display elements.

[0011] According to the invention, the display device has at least one cover over the display elements, made of a translucent and flexible, soft, or elastic flat material. This cover rests on the upper surfaces of the display elements, advantageously covering a large portion or more than 50% of the surface area of ​​the upper surfaces, and in particular, it covers all the upper surfaces of all display elements on the component carrier. The cover is attached to the display device and is thus part of it. This attachment will be discussed in more detail below. Finally, the cover and the display device form a single assembly. For example, the display device or this assembly can later be installed in an electrical appliance, such as a cooktop.

[0012] By using a translucent and flexible flat material as a cover, a kind of protective, leveling, or adaptation layer can be created between the display element or top surface and the underside of a display bezel or cover, etc., which runs over the display device. This allows, for example, unevenness to be compensated for and / or a protective function to be achieved.

[0013] Advantageously, the display device has a single cover, so that only one part needs to be attached to or mounted on the display device. Particularly advantageous is that the cover extends continuously over the display elements. This means that one cover can cover several or even all of the display elements of the display device. The cover can cover at least 50% of the surface of the component carrier, ideally forming a substantially closed and simply shaped area, for example, essentially a rectangle. This area then extends only as far over the component carrier as is necessary to cover the display elements. Therefore, it is not necessary for the cover to cover the entire component carrier, its mounting device, or the entire display device.

[0014] Due to the cover's translucency, it is virtually invisible from above and does not interfere with the display function. Further improved optical properties can be achieved by ensuring the cover has a flat top and / or bottom surface, at least above the display elements. This also improves the uniform contact of the display elements with the underside of the display bezel. Advantageously, the cover should have a consistent thickness, for example, across the entire surface above the display elements. The thickness can be relatively small, with a maximum of 5 mm. A thickness of 0.2 mm to 2 mm is advantageous, and 0.4 mm to 0.8 mm is particularly beneficial.

[0015] For fastening, the cover can be attached to the component carrier and / or the holding device on at least two sides, which can be opposite sides. This eliminates the need for a complex, for example, circumferential frame to secure the cover. A positive-locking fastening of the cover to the holding device or the component carrier is advantageous. A positive-locking fastening is particularly advantageous if it is releasable or can be manually released, for example, for repair purposes. For fastening, a snap-fit ​​or clamping connection that is automatically engaged upon placement can be provided, for example.

[0016] In a further embodiment of the invention, the cover may have a downward-curving edge along at least two sides, particularly advantageously precisely along two sides. This edge can be narrow, but it can also be wide enough to almost reach the height of the holding device. Fastening means for the aforementioned snap-fit ​​or clamping connection of the cover to the holding device are advantageously provided at this edge.

[0017] One possible material for manufacturing the cover is silicone, so the cover can be made of or consist of silicone. Ideally, this should be highly transparent silicone. It should be relatively soft and preferably has a Shore (A) hardness of 50 to 70, ideally around 60. It is also preferably electrically insulating and thermally insulating.

[0018] In a further embodiment of the invention, the cover can be designed as a type of mat or mat-like material, preferably with a rectangular base. Due to the material used, particularly soft or elastic silicone, the cover may not be particularly dimensionally stable. It preferably achieves its essential dimensional stability when it is attached to the holding device or the component carrier, i.e., to the display device. Even then, its stability is essentially only required in the direction of downward pressure on the cover or the display device.

[0019] In an advantageous embodiment of the invention, the component carrier has capacitive sensor elements to form a capacitive touch switch on the display device. A switching operation can be triggered by placing a finger on a cover in front of the capacitive sensor element. This is known, for example, from the aforementioned DE 102009036161 A1 and especially from EP 2809006 A1. The capacitive sensor elements should lie approximately in the same plane as, or extend in this plane, as the upper surfaces of the display elements. Advantageously, the capacitive sensor elements protrude slightly beyond the upper surfaces of the display elements. They should project at least 1 mm beyond them. However, not only the upper surfaces of the display elements should be in contact with or covered by the cover, but also the sensor elements.

[0020] It is advantageous to arrange a capacitive sensor element on the top surface of a display element or at the top of the display element. It is particularly advantageous if it is arranged laterally to the side of the top surface of the display or surrounds it. The capacitive sensor element can have several narrow longitudinal sections or even just cone-shaped projections; it does not need to be a continuous surface, as shown in EP 2809006 A1. Thus, the capacitive sensor element or its sections can be arranged laterally to the top surface of the display or roughly surround it.

[0021] In the invention, the upper surface of the display is indeed provided with an opaque coating. However, this coating has at least one cutout per display element for the illuminated display. No coating is provided in these cutouts, or light can pass through them in the corresponding form due to the cutout from the display element. Therefore, the upper surface of the display is first coated with a substantially large or full coating, and then this coating is cut out with a specific pattern or symbol shape, or the coating is removed. According to the invention, this removal of the coating is carried out using a laser. Since the coating is opaque, light is now transmitted through the exposed areas or cutouts above the upper surface of the display.

[0022] In an advantageous embodiment of the invention, the display surface or the coating is not overlaid by any other component on the component carrier or by the holding device, excluding the cover. Advantageously, the display surface or the coating is only overlaid by the capacitive sensor elements, if any are provided at all. This overhang can be small, however, and may be a maximum of 2 mm, preferably 0.7 mm to 1.5 mm.

[0023] In the invention, an electrical device according to the invention, comprising a previously described display device, has a display panel. A display is generated beneath this display panel by the display device. This display panel extends over the display device, concealing it or making it usable and, if necessary, very robust for the intended application. The display device is pressed against the display panel from below and thus rests against its underside. This offers the advantage of the aforementioned precise definition of the distances between the display elements and the underside of the display panel.

[0024] In a further embodiment of the invention, the electrical appliance can be a cooktop with a cooktop element that then serves as a display panel. The display is pressed against the underside of the cooktop element, which is advantageously a glass-ceramic cooktop. The cooktop element can have a textured underside with raised and recessed areas. Typically, this textured underside of a glass-ceramic cooktop is formed as a type of nub, as shown in DE 4104983 C1. The raised areas should have a maximum height of 1 mm, preferably only about 0.3 mm to 0.7 mm. The display panel then rests in the recesses between the raised areas on the underside of the cooktop element. Thus, the display panel can serve as a leveling or compensating element for the uneven texture on the underside of the cooktop element or, alternatively, on another display panel.Besides potentially improving the visual appearance by smoothing out these bumps and depressions, thus partially or even largely eliminating them so they are practically invisible, this also prevents damage to the aforementioned coating on the display surface when the structure, or especially the bumps, are pressed down. Such damage can be so severe that the coating is pushed through or scratched in unwanted areas, becoming translucent and resulting in an aesthetically unappealing design. Light can then escape in an undesirable way.

[0025] These and other features are evident not only from the claims but also from the description and the drawings, whereby the individual features, either alone or in combination, may be implemented in one embodiment of the invention and in other fields, and may represent advantageous and individually protectable embodiments for which protection is claimed here. The division of the application into individual sections and subheadings does not limit the general validity of the statements made therein. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] An embodiment of the invention is schematically illustrated in the drawings and is explained in more detail below. The drawings show: Fig. 1. An oblique view from above of a display device with a cover, Fig. 2 the display device off Fig. 1 without the cover, Fig. 3 a printed circuit board as component carrier of the display device Fig. 1, Fig. 4. An oblique view of a display element for a display device according to the Fig. 1 to 3 with rib-like capacitive sensor elements attached to the top surface, Fig. 5 a top view of the underside of a glass-ceramic cooktop with studs, Fig. 6 a side view of a cooktop according to the invention with a glass-ceramic cooktop plate accordingly Fig. 5, on the underside of which the display device is made Fig. 1 is pressed, Fig. 7. training accordingly Fig. 6 according to the state of the art without cover and Fig. 8 a strong schematic enlargement of a section from Fig. 6. DETAILED DESCRIPTION OF THE EXECUTION EXAMPLES

[0027] In the Fig. Figures 1 to 3 show a display device 11, in which Fig. 1 Specifically, a holding device 19 for a printed circuit board 13 with a cover 22. The printed circuit board 13 can be a conventional printed circuit board and has display elements 15 arranged on it, such as those known, for example, from EP 2809006 A1 in block-like form. The display elements 15 are assembled here, but are advantageously individual components. Alternatively, one of the rows of display elements can also be considered or designed as a single display element. The display elements 15 each have display surfaces 16, which have an opaque coating as mentioned above, applied to the otherwise transparent top surface and ensuring that no light can escape from the inside or below. Symbols 17 are then at least partially formed in this display surface 16, for which the coating has been removed, for example by a laser.This is known from the prior art; see, for example, the aforementioned DE 102009036161 A1. The symbols 17 can be numbers, letters, or any other symbols or areas. In order for this coating on the upper surface 16 of the display to be removed by laser, it should not be too hard, stable, or durable. This is why the aforementioned problem exists: if pressure is applied to a structure on the underside of a display panel, especially the raised bumps of a glass-ceramic cooktop, damage can occur. This damage can even be so severe that the coating is thinned, pushed through, or even damaged to such an extent that light can escape unintentionally.

[0028] The circuit board 13 is arranged in a holder-like mounting device 19, as is known per se and does not require further explanation here. The mounting device 19 has a wide circumferential rim on which hook-like projections 20 are provided on the opposite longitudinal sides.

[0029] As the Fig. 1 compared to the Fig. Figure 2 shows that a cover 22 is essentially flat and planar with a covering surface 23, roughly rectangular in shape, and covers a large part of the printed circuit board 13. The covering surface 23 has a constant thickness, for example, 0.4 mm. On both long sides, the cover 22 has a downward-facing edge 24 with recesses 25 that correspond to the projections 20. Thus, the cover 22 can be pulled or, so to speak, slipped over the holding device 19 with the printed circuit board 13 inside and fastened. This ensures that the Fig. The assembly shown in Figure 1 forms the finished display device 11. This display device 11 can then be, as shown in the Fig. 6 and Fig. 8 show that they can be installed in an electrical appliance, preferably a cooktop.

[0030] In the Fig. Figure 4 shows a possible alternative display element 15', which is also essentially block-shaped or cuboid, in particular according to the aforementioned EP 2809006 A1. Rib-like capacitive sensor elements 18 made of injection-molded elastomer material are formed on the upper surface of the display element 15'. This material is electrically conductive and electrically contacted downwards on the circuit board 13, as is known from the prior art. These capacitive sensor elements 18 also suffer from the problem that, when placed against the structured underside of a cover, in particular a glass-ceramic cooktop, as mentioned above, they may not make proper contact due to the aforementioned bumps. This can severely impair the functionality of a capacitive touch switch formed in this way.

[0031] In the Fig. Figure 5 shows a glass-ceramic cooktop 28 in a bottom view. It has a generally flat underside 29 from which round or oval studs 30 protrude. These studs 30 are arranged regularly with a few millimeters of space between them and have a height between 0.3 mm and a maximum of 1 mm. The studs 30 are a design feature of such glass-ceramic cooktops 28, but at the same time, they cause the aforementioned problems due to the non-flat underside of the glass-ceramic cooktop 28. The sectional enlargement of the Fig. Figure 8 shows these bumps even more clearly.

[0032] In Fig. Figure 6 shows a section of a cooktop 31 in its assembled state. The display unit 11 is attached to the underside 29 of the glass-ceramic cooktop 28. Fig. 1 pressed down, for example with the springs 33 visible below, which press against the underside of the retaining device 19 and rest on a cooktop housing, as is known from the prior art. Further functional units, especially heating elements, are also arranged under the glass-ceramic cooktop 28, but these are not shown here because they are irrelevant. It can be seen that the display device 11 rests with the entire surface or cover surface 23 of the cover 22 against the underside 29 of the glass-ceramic cooktop 28. Naturally, as the Fig. Figure 8, enlarged, shows the studs 30 in the cover area 23.

[0033] The illustration of a conventional 31' cooktop Fig. Figure 7 shows how a display device 11' with display elements 15 is normally pressed onto the underside 29' of a glass-ceramic cooktop 28' provided with studs 30'. The display elements 15, with their upper display surfaces 16, are pressed directly against the underside 29' of the glass-ceramic cooktop 28' from below. Thus, their studs 30' partially rest directly against the upper display surfaces and can press through, scratch, or damage them. This can lead to the aforementioned undesirable light phenomena, backlighting, or blurring of illuminated symbols. The invention aims to prevent these problems.

[0034] In the Fig. Figure 8 is an enlarged section corresponding to the Fig. Figure 6 shows that on the circuit board 13, a normal display element 15 is shown on the left. Fig. 2 and Fig. Figure 3 shows the display element 15. The cover 22 with the covering surface 23 is pressed onto its upper display surface 16. This is evident from the fact that the display element 15, with its upper display surface 16, is pressed slightly into the covering surface 23. However, this is not a problem due to the flexibility or softness of the cover 22 material. Furthermore, it can be seen that an LED 14 is mounted on the circuit board 13 within the display element 15 to shine upwards through the display element 15, thereby also illuminating the translucent cover 22 and the glass-ceramic cooktop 28.

[0035] To the right of display element 15 is a modified display element 15' accordingly. Fig. Figure 4 shows that it has upward-pointing capacitive elastic sensor elements 18 on its upper surface. These are, slightly exaggerated here, pressed more deeply into the covering surface 23 of the cover 22 due to their narrow dimensions.

[0036] Above all, it is from the Fig.Figure 8 also shows how the cover surface 23 adapts to the nubs 30 on the underside 29 of the glass-ceramic cooktop 28. It largely conforms to the underside 29, which forms recesses between the nubs 30. This is important to prevent air pockets and light from passing through the air-boundary layer, allowing the light to pass directly from the cover material 22 into the glass-ceramic cooktop material 28. Another reason for minimizing air pockets and ensuring good, full-surface contact is that otherwise the function of the capacitive sensor elements 18 on the display element 15' would be impaired. However, sufficiently good adaptability can be achieved by selecting an appropriate material for the cover 22.For this purpose, a naturally transparent, electrically insulating, and as flexible a plastic as possible is chosen as the material for the cover 22, preferably silicone. This also ensures advantageous heat resistance for use in the cooktop 31. In particular, if a hot pot is placed on the area above the display unit 11, where the glass-ceramic cooktop plate 28 forms a display panel, the heat radiation from the pot downwards and the heat conduction can potentially damage the display elements 15. The additional cover 22 significantly reduces this problem.

Claims

[1] Electrical device (31) with a display device (11), wherein: - the electrical device (31) has a display panel (28) under which the display device (11) is arranged, - the display device (11) is pressed onto the underside (29) of the display panel (28) by means of a cover (22) and thus rests against the underside (29), wherein the display device (11) comprises: - a flat component carrier (13), - at least two cuboid or block-like display elements (15) on the component carrier (13), wherein the display elements (15) have display tops (16) which point away from the component carrier (13) and which lie in a common plane, - light sources (14) in the display elements (15), - a holding device (19) for the component carrier (13), where - the display device (11) has at least the cover (22) over the display elements (15) made of translucent and flexible flat material, - the cover (22) rests on the display tops (16), - the cover (22) is attached to the display device (11) as part thereof, - the cover (22) forms a structural unit with the display device (11), characterized by that the display top sides (16) are provided with an opaque coating which has at least one cutout (17) without a coating per display element (15), wherein the cutout (17) is produced by removing the coating by means of a laser. [2] Electrical appliance according to claim 1, characterized bythat it is a hob (31) with a hob plate (28) as a display panel, wherein the display device (11) is pressed onto the underside (29) of the hob plate (28), wherein the hob plate (28) has a structure with elevations (30) and depressions on the underside (29), and the cover (22) rests in the depressions between the elevations (30) on the underside (29) of the hob plate (28). [3] Electrical appliance according to claim 1 or 2, characterized by that the display device (11) has a single cover (22), wherein the cover (22) runs continuously over the display elements (15) and covers at least 50% of the area of ​​the component carrier (13). [4] Electrical appliance according to one of the preceding claims, characterized by that the cover (22) above the display elements (15) has a flat top side and / or a flat bottom side. [5] Electrical appliance according to one of the preceding claims, characterized bythat the cover (22) is fastened on at least two sides to the component carrier (13) and / or to the holding device (19) for the component carrier (13), wherein it is releasably fastened in a form-fitting manner by means of a snap-in or clamping connection (20, 25) which is automatically produced when it is put on. [6] Electrical device according to claim 5, characterized by that the cover (22) has a downwardly drawn edge (24) running along at least two sides, in particular down to below the component carrier (13), preferably with fastening means (25) for the snap-in or clamping connection. [7] Electrical appliance according to one of the preceding claims, characterized by that the cover (22) has or is made of silicone. [8] Electrical appliance according to one of the preceding claims, characterized bythat the component carrier (13) has capacitive sensor elements (18) for forming a capacitive touch switch on the display device (11), wherein the capacitive sensor elements (18) lie approximately in the same plane as the display top sides (16) of the display elements (15) or slightly above. [9] Electrical device according to claim 8, characterized by that a capacitive sensor element (18) is arranged on the upper side (16) of a display element (15) or on top thereof, wherein the capacitive sensor element (18) is arranged laterally next to the display upper side (16) or surrounds the display upper side (16). [10] Electrical appliance according to one of the preceding claims, characterized by that the display top side (16) or the coating is neither projected over by another component on the component carrier (13) nor by the holding device (19).

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