Decorative parts with welded panels, carriers, and thin film layer structures

Abstract

This invention relates to a decorative element comprising: a panel having a transparent covering layer having a visible surface facing an observer, and the panel further having a thermoplastic decorative film disposed on the side of the covering layer facing away from the observer, the main surface of the decorative film being coated with a decorative coating; a carrier disposed on the side of the panel, which constitutes one or more thermoplastic webs, the webs respectively constituting T-shaped or mushroom-shaped protrusions extending toward the panel in cross-section, and the protrusions being welded to the decorative film; a film layer structure having at least two flat films sandwiched between the panel and the carrier; a first film disposed adjacent to the panel with its main surface therein, and a second film disposed adjacent to at least the web of the carrier; wherein the film layer structure has one or more openings respectively penetrated by the webs, wherein the openings formed by at least the first film are sized such that the T-shaped or mushroom-shaped protrusions in cross-section are accommodated therein.

Description

Technical Field

[0001] This invention relates to a decorative element, which essentially comprises three parts: a panel, a thin-film layer structure, and a carrier. The panel serves to provide an optically attractive visible surface, having decorations, symbols, and / or backlighting surfaces produced, for example, by a decorative coating of a decorative film serving as a substrate. The thin-film layer structure serves to provide capacitive touch sensors and / or light distribution, such as uniform illumination of the light-emitting surface. The carrier serves to secure the decorative element to a load-bearing component of a motor vehicle, such as a dashboard, center console, etc. The touch sensors and backlighting require precise and permanent positioning of the thin-film layer structure. For this purpose, an arrangement where the thin-film layer structure is clamped between the carrier and the panel is typically chosen. The problem here is that only a connection that completely eliminates optical damage to the panel's decorative coating is feasible. A material-locking connection caused by thermal welding is preferred in itself because it is easily achievable and has high production yield in terms of manufacturing technology, but it carries the risk of damage to the decorative coating. Background Technology

[0002] Against this backdrop, there is a need for a solution for decorative elements having welded panels and a carrier, and a thin film layer structure clamped between them, without causing optical damage to the decorative coating belonging to the panels, particularly with improvements in the robustness and durability of the fixed thin film layer structure, and especially with the ability to be manufactured cost-effectively. This objective is achieved by the decorative element according to claim 1. Equally advantageous applications and methods of manufacture are the subject of the co-pending claims. Advantageous configurations are the subject of the dependent claims. It should be noted that the features individually listed in the claims can be combined with each other in any technically meaningful manner and show further improvements to the invention. The invention is additionally characterized and described, particularly in conjunction with the accompanying drawings. Summary of the Invention

[0003] This invention relates to a decorative element having a panel, a carrier, and a thin film layer structure clamped between the panel and the carrier. The panel has a transparent overlay, preferably made of a transparent thermoplastic and having a visible surface facing the observer. The term "visible surface" should be interpreted broadly: it can be a decorative surface designed purely for viewing, or a touch or operational surface facing the observer, configured to perform manipulative input via touch and / or operation, so that the decorative element can serve as an input device for a human-machine interface. The visible surface preferably constitutes a touch-sensitive array of touch surfaces, monitored by an array of electrodes forming a measuring capacitance and associated measuring electronics. Each touch surface may correspond to one or more light-emitting surfaces. According to the invention, a thermoplastic decorative film is provided, lockably connected to the overlay material, having a decorative coating applied, for example, printed, on its main surface facing the overlay. The decorative film preferably has a transparent film substrate, which is coated in a semi-transparent to opaque manner in certain areas to form the decorative coating. Optionally, the panel constitutes at least one backlit luminescent surface visible through the cover layer.

[0004] A carrier arranged on the side of the panel facing away from the observer constitutes one or more thermoplastic webs, each web forming a protrusion extending toward the panel, the protrusion being T-shaped or mushroom-shaped when viewed in a cross-section perpendicular to the visible surface. The T-shaped or mushroom-shaped protrusion in cross-section is welded to the decorative film in a material-locking manner with its surface pointing toward the panel.

[0005] In cases where a light-emitting surface is optionally present, one or more light-emitting devices, such as light-emitting diodes applied to a printed circuit board in an SMD structure, are optionally fixed on a carrier and arranged to provide backlighting for a light-emitting surface formed by a panel.

[0006] The substantially flat film layer structure clamped between the panel and the carrier has at least two films. The films are stacked, for example, in a direction perpendicular to the visible surface, with one of their main surfaces adjacent to each other, and form a loose bond, for example, at least in the main region of their adjacent main surfaces, which is essentially secured only by the clamping between the panel and the carrier.

[0007] According to the invention, a first film close to the observer is arranged to fully abut the panel with its main surface, while a second film is arranged to at least abut the web of the carrier. The first film preferably abuts the panel with its main surface. According to the invention, the film layer structure has one or more openings, each passing through the web of the carrier. According to the invention, the size of the openings in the film layer structure, each composed at least of the first film of the film layer structure, is determined such that a T-shaped or mushroom-shaped protrusion in cross-section, obtained by thermal deformation or warping, is accommodated in the opening formed in the first film. Preferably, the T-shaped or mushroom-shaped protrusion in cross-section is accommodated in the corresponding opening of the first film in a form-locking manner. When a T-shaped or mushroom-shaped protrusion in cross-section is accommodated in the opening of the first film with such a gap in a direction perpendicular to the visible surface, the gap is no more than 0.3 mm, preferably no more than 0.1 mm, and the accommodation is particularly understood to be "form-locking".

[0008] On the one hand, this results in reliable fixation of the thin film layer structure in a direction parallel to the visible surface, while the material-locking connection between the panel and the carrier on the panel-facing surface of the mushroom head, according to the invention, ensures that no optical damage to the decorative coating of the decorative film occurs, for example, due to thermal overload, thus guaranteeing reliable fixation of the carrier and the panel without damaging the decoration of the panel. More precisely, the material-locking, thermally induced connection between the panel and the carrier can be achieved in the area below the decorative coating as seen from the observer's position, thus making it not absolutely necessary to obtain the visual appearance of the decorative coating, for example, by using edge welding, the disadvantage of which is that it cannot guarantee reliable and permanent fixation of the thin film layer structure.

[0009] At least the web of the carrier is preferably made of opaque thermoplastic, for example, to prevent light from passing between the regions of the thin film layer structure separated by the web.

[0010] The thin-film layer structure preferably includes a thin-film substrate with a conductive coating constituting an electrode array and a semi-transparent diffuse film. More preferably, the diffuse film is the first film of the thin-film layer structure, i.e., the film closer to the observer, while the thin-film substrate with the conductive coating is the second film, the film farther from the observer. The diffuse film is understood to be a film made of a semi-transparent film that diffuses light. The diffuse film ensures uniform light distribution with a small number of light sources, without the need to embed a light-scattering layer in the panel.

[0011] Preferably, the light trap is arranged adjacent to the carrier so as to backlight the thin film layer structure, particularly the first thin film, with the light of at least one light-emitting device. The plurality of light-emitting surfaces, formed by the panel, are preferably backlit by light from one and the same light-emitting device via the thin film layer structure, particularly its diffuser film. For example, the light trap is made of a material that improves optical reflection, or at least coated with such a material on the surface facing the light-emitting device. The light trap is preferably made of white thermoplastic. For example, the carrier is made of white and dark, preferably black, thermoplastic by a multi-color injection molding process. In a preferred embodiment, the light trap is mechanically locked to the carrier.

[0012] Preferably, the thermoplastic decorative film and the T-shaped or mushroom-shaped protrusions in the cross-section are ultrasonically welded.

[0013] The panel is preferably manufactured by spraying a decorative film onto the front of a transparent thermoplastic to form a covering layer.

[0014] In one design, the openings in the second film of the thin film layer structure coincide with the openings in the first film. Preferably, the openings in the second film of the thin film layer structure are narrower than the corresponding openings in the first film of the thin film layer structure formed by the same web.

[0015] Preferably, at least in the regions where openings are formed, the films of the thin film layer structure are welded in a material-locking manner.

[0016] Preferably, the maximum thickness of the decorative film does not exceed 200 micrometers.

[0017] Preferably, the thin film layer structure has at least one additional notch, wherein the electronic display, especially the electronic pixel matrix display, is fixed to the carrier, and an observer can see the display area of ​​the electronic display through the panel and the notch.

[0018] The present invention also relates to the application of a decorative element of one of the previously described embodiments in a motor vehicle.

[0019] The present invention also relates to a method for manufacturing decorative parts, comprising the following steps: In a preparation step, a panel is prepared having a transparent cover layer with a visible surface facing an observer, and a thermoplastic decorative film disposed on the side of the cover layer facing away from the observer and connected to the cover layer in a material-locking manner, the thermoplastic decorative film having a decorative coating applied to its main surface facing the cover layer. In another preparation step, a carrier disposed on the side of the panel facing away from the observer is prepared, which constitutes one or more thermoplastic webs, wherein the webs respectively constitute energy guides extending toward the panel. Optionally, one or more light-emitting devices fixed to the carrier are provided for backlighting the light-emitting surface.

[0020] Furthermore, a substantially flat thin-film layer structure with at least two films is prepared. For example, it is placed on a carrier or panel in a pre-assembly step prior to subsequent ultrasonic welding and is pre-fixed, for example, by means of tabs or so-called quick nuts.

[0021] In the following steps according to the invention, ultrasonic welding of the carrier and the panel is performed, wherein when a cross-section perpendicular to the visible surface is observed, the energy director melts, for example, fused into a T-shaped or mushroom-shaped protrusion, such that the protrusion is welded to the decorative film in a material-locking manner with its surface pointing towards the panel, and the film layer structure is clamped between the panel and the carrier; wherein the main surface of the first film of the film layer structure is arranged adjacent to the panel, and the second film of the film layer structure is arranged at least adjacent to the web of the carrier. Here, the film layer structure has one or more openings respectively passing through the web, wherein the openings formed by at least the first film are respectively sized such that the energy director, which is fused into a T-shaped or mushroom-shaped protrusion during ultrasonic welding, is accommodated therein. Preferably, the T-shaped or mushroom-shaped protrusion in cross-section is locked in place within the corresponding opening of the first film.

[0022] When a T-shaped or mushroom-shaped protrusion in cross-section is accommodated in an opening of the first film in a gap perpendicular to the visible surface, such gap is no more than 0.3 mm, preferably no more than 0.1 mm, then the accommodation is particularly understood to be “shape-locked”.

[0023] On the one hand, this results in reliable fixation of the thin film layer structure in a direction parallel to the visible surface, while the material-locking connection between the panel and the carrier on the panel-facing surface of the mushroom head, according to the invention, ensures that no optical damage to the decorative coating of the decorative film occurs, for example, due to thermal overload, thus guaranteeing reliable fixation of the carrier and the panel without damaging the decoration of the panel. More precisely, the material-locking, thermally induced connection between the panel and the carrier can be achieved in the area below the decorative coating as seen from the observer's position, thus making it not absolutely necessary to obtain the visual appearance of the decorative coating, for example, by using edge welding, the disadvantage of which is that it cannot guarantee reliable and permanent fixation of the thin film layer structure.

[0024] According to a preferred variation of the method of the present invention, the thin film layer structure has a thin film substrate comprising a conductive coating constituting an electrode array, preferably as the second thin film, and a semi-transparent diffuse thin film, preferably as the first thin film.

[0025] In a preferred design, the panel is preferably manufactured in a step preceding the preparation step by spraying a decorative film onto the front of a transparent thermoplastic to form a covering layer.

[0026] Preferably, during ultrasonic welding, the first and second film materials of the thin film layer structure are welded together in a locking manner, at least in the area of ​​the opening.

[0027] Preferably, the maximum thickness of the decorative film does not exceed 200 micrometers. Attached Figure Description

[0028] The invention will be explained in more detail with reference to the following accompanying drawings. These drawings are to be understood as illustrative only and represent preferred embodiments only. The drawings show:

[0029] Figure 1 A cross-sectional view of one embodiment of the decorative element 1 according to the invention is shown.

[0030] Figure 2 The illustration shows the method of manufacturing according to the present invention. Figure 1 A cross-sectional view of the method of decorative element 1 in the middle.

[0031] Figure 3 The illustration shows the method of manufacturing according to the present invention. Figure 1 Another sectional view of the method of decorative element 1 in the middle. Detailed Implementation

[0032] Figure 1 An embodiment of the decorative element 1 according to the invention is shown, the decorative element 1 having a panel 2, a carrier 12, and a thin film layer structure 4 clamped between the panel and the carrier. The panel 2 includes a transparent cover layer 2a, which is formed by spraying a decorative film 2b onto the front of a transparent thermoplastic. The cover layer 2a constitutes a visible surface 8 facing the observer. The term "visible surface" should be interpreted broadly: it can be a purely decorative surface or a touchable or operational surface facing the observer, so as to perform manipulative input by touch and / or operation. For example, the visible surface forms a touch-sensitive touch surface array, monitored by an array of electrodes forming a measuring capacitance and associated measuring electronics. Each touch surface may correspond to one or more light-emitting surfaces.

[0033] A decorative film 2b, made of thermoplastic material, is applied to the front side of the decorative layer 2a, thereby locking the decorative film material into the cover layer 2a. The decorative film 2b is coated, for example printed with a decorative coating 10, on its main surface facing the decorative layer 2a and has a maximum thickness (also referred to as strength) not exceeding 200 μm.

[0034] The carrier 12, arranged on the observer-away side 9 of the panel 2, comprises a plurality of webs 3 made of opaque thermoplastic, wherein the webs 3 are integrally connected to the rest of the carrier 12. Each web 3 comprises a protrusion 5 extending toward the panel 2, the protrusion being T-shaped or mushroom-shaped when viewed in a cross-section perpendicular to the visible surface 8. The T-shaped or mushroom-shaped protrusion 5 in the cross-section is welded to the observer-away main surface of the decorative film 2b in a material-locking manner with its surface pointing toward the panel 2. In cases where light-emitting surfaces are optionally present, one or more light-emitting devices, such as light-emitting diodes applied to a printed circuit board in an SMD structure, are optionally fixed to the carrier 12 and arranged for backlighting one or more light-emitting surfaces constituted by the panel 2.

[0035] The substantially flat film layer structure 4, clamped between panel 2 and carrier 12, has at least two films: a first film 4a closer to the observer and panel 2, and a second film 4b farther from the observer and panel 2. Films 4a and 4b are stacked in a direction perpendicular to the visible surface 8, with one of their main surfaces abutting each other, and forming a loose bond, for example, at least in the main region of their adjacent main surfaces, which is essentially secured only by clamping between panel 2 and carrier 12 or its web 3. Here, the web 3 of carrier 12 is made of opaque thermoplastic to prevent light from passing between the web-separated areas of film layer structure 4.

[0036] Therefore, the first film 4a, which is closer to the observer, is fully adjacent to the panel 2 with its main surface, while the second film 4b is arranged at least adjacent to the web 3 of the carrier 12. For this purpose, the film layer structure 4 has a plurality of openings 6a, 6b through which the web 3 of the carrier 12 passes. Here, the size of the opening 6a in the film layer structure 4, which is at least composed of the first film 4a, is determined such that the protrusions 5, which are T-shaped or mushroom-shaped in cross-section and obtained through thermal deformation or warping, are shape-locked into the openings 6a formed in the first film 4a. When the protrusions 5, which are T-shaped or mushroom-shaped in cross-section, are accommodated in the openings 6a of the first film 4a with such a gap in a direction perpendicular to the visible surface, the gap does not exceed 0.3 mm, preferably 0.1 mm, and the accommodation is particularly understood to be "shape-locked".

[0037] On the one hand, this results in the reliable fixation of the thin film layer structure 4 in a direction parallel to the visible surface 8, while the material-locking connection between the panel 2 and the carrier 12 on the mushroom head or T-faced surface of the panel 2, according to the invention, ensures that no optical damage to the decorative coating 10 of the decorative film 2b occurs, for example due to thermal overload, thus guaranteeing the reliable fixation of the carrier 12 and the panel 2 without damaging the decoration of the panel 2. More precisely, the material-locking, thermally induced connection between the panel 2 and the carrier 12 can be achieved in the area below the decorative coating 10 as seen from the observer's position, thus making it not absolutely necessary to obtain the visual appearance of the decorative coating 10, for example, by using edge welding, the disadvantage of which is that it cannot guarantee the reliable and permanent fixation of the thin film layer structure 4.

[0038] In this embodiment, the thin film layer structure 4 includes a thin film substrate having a conductive coating constituting an electrode array as a second thin film 4b and a semi-transparent diffuse film as a first thin film 4a. In a design not shown, the openings 6b in the second thin film 4b of the thin film layer structure coincide with the openings 6a in the first thin film 4a. In the illustrated embodiment, the openings 6b in the second thin film 4b of the thin film layer structure 4 are narrower than the openings 6a in the first thin film 4a of the thin film layer structure 4 through which the same web 3 passes. Preferably, the heat introduced during ultrasonic welding is sufficient to cause localized thermal welding of the two thin films 4a and 4b of the thin film layer structure 4, at least in the regions of their openings 6a and 6b.

[0039] Reference Figure 2 and Figure 3 Description of the manufacture according to the present invention Figure 1 The method of decorative element 1 shown.

[0040] exist Figure 2 The panel 2 is fabricated in the shown preparation steps. The panel has a transparent cover layer 2a with a visible surface 8 facing the observer, material-locked together, and a thermoplastic decorative film 2b disposed on the side of the cover layer 2a facing away from the observer and connected to the cover layer 2a in a material-locked manner. The thermoplastic decorative film has a decorative coating 10 coated on its main surface facing the cover layer 2a. In steps preceding this preparation step, for example, the panel 2 is manufactured by spraying a decorative film 2b with the decorative coating 10 onto the front of a transparent thermoplastic plastic surface to form the cover layer 2a.

[0041] like Figure 2As shown, a thin film layer structure 4 is also prepared having at least two substantially flat thin films, namely a first thin film 4a and a second thin film 4b. The thin films 4a and 4b are stacked in a direction perpendicular to the visible surface 8, with one of their main surfaces abutting each other and forming a loose bond, for example, at least in the main regions of their adjacent main surfaces. The first thin film 4a of the thin film layer structure 4 is placed on the side 9 of the panel 2 facing away from the observer, such that the observer-facing main surface is fully abutting the side 9 of the panel 2 facing away from the observer. Optionally, the thin film layer structure 4 can be pre-fixed to the panel by means of tabs or so-called quick nuts. The thin film layer structure 4 includes a thin film substrate having a conductive coating forming an electrode array as the second thin film 4b and a translucent diffuse film as the first thin film 4a.

[0042] In addition, Figure 3 In another preparation step shown, a carrier 12 is prepared on the side 9 of the panel facing away from the observer, which constitutes a plurality of webs 3, wherein each web 3 constitutes an energy guide 11 extending toward the panel 11, wherein each energy guide 11 is respectively engaged in the relevant openings 6a, 6b of the thin film layer structure 4.

[0043] In a subsequent step according to the invention, ultrasonic welding is performed on the carrier 12 and the panel 3, wherein when a cross-section perpendicular to the visible surface 8 is observed, the energy guide 11 fuses into a T-shaped or mushroom-shaped protrusion 5, such as... Figure 1 As shown, the surface of the film pointing towards panel 2 is welded to the decorative film 2b in a material-locking manner, and the film layer structure 4 is clamped between panel 2 and carrier 12. Here, the main surface of the first film 4a of the film layer structure 4 is arranged adjacent to panel 2, while the second film 4b of the film layer structure 4 is arranged adjacent to at least the web 3 of carrier 12. Here, the openings 6a formed by the first film 4a in the film layer structure 4 are sized such that the energy guide 11, which fuses into a T-shaped or mushroom-shaped protrusion 5 during ultrasonic welding, is shape-locked therein. When the protrusion 5, which has a T-shaped or mushroom-shaped cross-section, is accommodated in the opening 6a of the first film 4a with such a gap in the direction perpendicular to the visible surface, the gap does not exceed 0.3 mm, preferably 0.1 mm, and the accommodation is particularly understood to be "shape-locked".

[0044] As described above, this results in the reliable fixation of the thin film layer structure 4 in a direction parallel to the visible surface 8, while the material locking connection between the panel 2 and the carrier 12 on the surface of the mushroom head or T facing the panel 2 according to the invention ensures that no optical damage to the decorative coating 10 of the decorative film 2b occurs, for example due to thermal overload, thereby ensuring the reliable fixation of the carrier 12 and the panel 2 without damaging the decoration of the panel 2.

[0045] In one design not shown, the opening 6b in the second film 4b of the thin film layer structure coincides with the opening 6a in the first film 4a. In the illustrated embodiment, the opening 6b in the second film 4b of the thin film layer structure 4 is narrower than the opening 6a in the first film 4a of the thin film layer structure 4, through which the same roll 3 passes. Preferably, the arrangement is such that the heat introduced during ultrasonic welding is sufficient to cause localized thermal welding of the two films 4a, 4b of the thin film layer structure 4, at least in the region of their openings 6a, 6b.

Claims

1. A decorative element (1), comprising: Panel (2) having a transparent cover layer (2a) having a visible surface (8) facing the observer, and the panel also having a thermoplastic decorative film (2b) disposed on the side of the cover layer (2a) facing away from the observer and connected to the cover layer (2a) in a material-locking manner, wherein the panel (2) constitutes at least one backlit luminescent surface. A carrier (12) arranged on the side (9) of the panel (2) away from the observer, the carrier forming one or more thermoplastic webs (3), wherein each web (3) forms a protrusion (5) extending toward the panel (2) for welding to the panel (2). One or more light-emitting devices fixed on a carrier (12) are used to backlight the light-emitting surface; The thin film layer structure (4) is sandwiched between the panel (2) and the carrier (12) and is flat; The film layer structure (4) has one or more openings (6a, 6b) respectively passed through the web (3), characterized in that a decorative coating (10) is coated on the main surface of the decorative film facing the cover layer (2a), and the protrusions (5) are T-shaped or mushroom-shaped when viewed in cross-section perpendicular to the visible surface (8), and the T-shaped or mushroom-shaped protrusions (5) are welded to the decorative film (2b) with their surfaces facing the panel (2) in a material-locking manner. The film layer structure (4) includes at least two film layers (4a, 4b), wherein the first film (4a) is arranged adjacent to the panel (2) with its main surface, and the second film (4b) is arranged adjacent to the web (3) of the carrier (12). An opening (6a) formed by at least the first film (4a) is sized such that a T-shaped or mushroom-shaped protrusion (5) in cross-section is accommodated therein, the decorative film (2b) having a transparent film substrate, which is translucent to opaque after being coated with a decorative coating (10).

2. The decorative element (1) according to claim 1, wherein the thin film layer structure (4) has a thin film substrate constituting an electrode array of conductive coating as a second thin film (4b), and a translucent diffuse film as a first thin film (4a).

3. The decorative element (1) according to claim 1, wherein the light trap is arranged adjacent to the carrier (12) so as to backlight the first film (4a) of the thin film layer structure (4) by means of light from at least one light-emitting device.

4. The decorative part (1) according to claim 1, wherein the thermoplastic decorative film (2b) and the T-shaped or mushroom-shaped protrusions (5) in the cross section are respectively welded by means of ultrasonic waves.

5. The decorative element (1) according to claim 1, wherein the panel (2) is manufactured by spraying the decorative film (2b) with a transparent thermoplastic front to form the covering layer (2a).

6. The decorative element (1) according to claim 1, wherein the opening (6b) of the second film (4b) of the film layer structure (4) is constructed to be narrower than the opening (6a) of the first film (4a) of the film layer structure (4) through which the same web (3) passes.

7. The decorative element (1) according to claim 1, wherein in the region of the opening (6a, 6b), the films (4a, 4b) of the film layer structure (4) are welded in a material-locking manner.

8. The decorative element (1) according to claim 1, wherein the maximum thickness of the decorative film (2b) of the panel (2) does not exceed 200 micrometers.

9. The decorative element (1) according to claim 1, wherein the T-shaped or mushroom-shaped protrusion (5) in the cross-section is received in the opening (6a) of the first film (4a) in a slit direction perpendicular to the visible surface (8), the slit not exceeding 0.3 mm.

10. The decorative element (1) according to claim 1, wherein the thin film layer structure (4) has at least one additional notch and an electronic display fixed to the carrier (12), wherein an observer can see the display area of ​​the electronic display through the panel (2) and the notch.

11. A method of applying the decorative element (1) according to any one of claims 1 to 7, in a motor vehicle.

12. A method for manufacturing a decorative part (1), comprising the following steps: Prepare a panel (2) having a transparent cover layer (2a) having a visible surface (8) facing the observer, and the panel also having a thermoplastic decorative film (2b) disposed on the side of the cover layer (2a) facing away from the observer and connected to the cover layer (2a) in a material-locking manner, wherein the panel (2) constitutes at least one backlighting surface; A carrier (12) is prepared and arranged on the side (9) of the panel (2) facing away from the observer, which constitutes one or more thermoplastic webs (3), wherein the webs (3) respectively constitute energy guides (11) extending toward the panel (2); wherein one or more light-emitting devices fixed on the carrier (12) are provided for backlighting the light-emitting surface. Prepare a substantially flat thin film layer structure (4), wherein the thin film layer structure (4) has one or more openings (6a, 6b); The ultrasonic welding carrier (12) and the panel (2) are performed such that one or more openings (6a, 6b) pass through the web (3) respectively, and the thin film layer structure (4) is clamped between the panel (2) and the carrier (12). Its features are, The thermoplastic decorative film (2b) is coated with a decorative coating (10) on its main surface facing the cover layer (2a); wherein, when viewed in a cross-section perpendicular to the visible surface (8), the energy guide (11) is fused into a T-shaped or mushroom-shaped protrusion (5), such that the protrusion (5) is welded to the decorative film (2b) in a material-locking manner with its surface facing the panel (2), the film layer structure (4) having at least two films (4a, 4b), wherein the first film (4a) of the film layer structure (4) a) The first main surface is arranged adjacent to the panel (2), and the second film (4b) of the thin film layer structure (4) is arranged adjacent to the web (3) of the carrier (12), wherein the opening (6a) formed by at least the first film (4a) is sized such that an energy guide (11) that is thermally deformed into a T-shape or mushroom shape during ultrasonic welding is accommodated therein, and the decorative film (2b) has a transparent film substrate that is translucent to opaque after being coated with a decorative coating (10).

13. The method according to claim 12, wherein the thin film layer structure (4) has a thin film substrate with a conductive coating constituting an electrode array as the second thin film (4b), and a semi-transparent diffuse film as the first thin film (4a).

14. The method of claim 12, wherein the panel (2) is manufactured by spraying the decorative film (2b) with a transparent thermoplastic front to form the cover layer (2a).

15. The method according to claim 12, wherein the opening (6b) formed by the second film (4b) is narrower than the opening (6a) of the first film (4a) of the film layer structure (4) through which the same web (3) passes.

16. The method according to claim 12, wherein during ultrasonic welding, the first film (4a) and the second film (4b) of the thin film layer structure (4) are welded together in a locking manner in the region of the openings (6a, 6b).

17. The method according to claim 12, wherein, The maximum thickness of the decorative film (2b) is no more than 200 micrometers.

18. The method according to claim 12, wherein the T-shaped or mushroom-shaped protrusion (5) in the cross-section is received in the opening (6a) of the first film (4a) in a slit direction perpendicular to the visible surface (8), the slit not exceeding 0.3 mm.

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