How to Apply Decorative Films onto Non-Planar Surfaces

Abstract

A method for applying an essentially rigid decorative film (2) having a decorative layer (24) onto a non-planar surface (16), preferably an exterior body skin (10) of an automobile (1), comprising the steps of: a) providing a decorative film (2); b) applying an adhesive layer (26) onto the decorative film (2); c) applying the decorative film (2) provided with an adhesive layer (26) onto an adhesive support film (27) to form a sandwich film (19); d) cutting a predetermined pattern of compression slits and linear expansion slits in the decorative film, the compression slits extending away from each other in a star shape or in a diamond shape design, the compression slits and the expansion slits penetrating the decorative film in the thickness direction; e) applying a sandwich film (19) onto the non-planar surface (16), wherein the sandwich film (19) is conformed to the convex areas (17) of the non-planar surface (16) by stretching the adhesive support film (27) and the decorative film (2), and wherein the sandwich film (19) is conformed to the concave areas (18) of the non-planar surface (16) by compressing the adhesive support film (27) and the decorative film (2).

Description

[Technical field]

[0001] The present invention relates to a method for applying an essentially rigid decorative film onto non-flat surfaces according to the preamble of claim 1. It further relates to a decorative film suitable for this purpose, to a film composite comprising such a film, and to a vehicle, in particular a motor vehicle, having a body skin on which such a decorative film has been applied by a method according to one of the enclosed claims. [Background technology]

[0002] Car customers often want to customize the exterior of their vehicles to suit their tastes. Until now, this has been possible by customizing the vehicle's paint or partial paint job or by wrapping the vehicle's skin with a film, but such individual vehicle designs can only be modified with considerable effort, especially when the situation demands it. For decorative film wrapping, the decorative film must be flexible, stretchable and compressible, which is difficult with thicker and more rigid decorative films. It may also be desirable to flexibly adapt the vehicle's appearance to specific driving purposes, such as a serious and restrained appearance for use as a commercial vehicle or a brightly colored appearance for a beach surfing holiday.

[0003] [Prior art] It is already known to cover curved or inclined surfaces with highly flexible, stretchable and compressible decorative films, but until now this has not been possible with rigid films such as wood veneers or e-paper films. It is also known to provide a vehicle body with displays that are activated using e-paper technology and can switch between different visual appearances, but until now this has only been possible on flat surfaces of the vehicle body. Summary of the Invention

[0004] It is an object of the present invention to identify a method for applying a decorative film onto a non-flat surface, which allows the decorative film to be flexibly adapted to the surface of any three-dimensional shape.

[0005] This object is solved by the features of claims 1 and 2.

[0006] A first solution to this object is a method for applying an essentially rigid decorative film having a decorative layer onto a non-planar surface, preferably onto the body skin of an automobile, comprising: a) providing a decorative film; b) applying an adhesive layer onto the decorative film; c) applying the decorative film provided with an adhesive layer onto an adhesive support film to form a sandwich film; d) cutting a predetermined pattern of compression slits and linear expansion slits into the electronic paper film, the compression slits extending away from each other in a star shape or designed in a diamond shape, the compression slits and the expansion slits penetrating the decorative film in a thickness direction; e) applying a sandwich film onto the non-planar surface, the sandwich film conforming to convex areas of the non-planar surface by stretching the adhesive support film and the decorative film, and the sandwich film conforming to concave areas of the non-planar surface by compressing the adhesive support film and the decorative film.

[0007] A second solution to this object is a method for applying an essentially rigid decorative film having a decorative layer onto a non-planar surface, preferably onto the body skin of an automobile, comprising the steps of: a) providing a decorative film; b) applying an adhesive layer onto the decorative film; c') cutting a predetermined pattern of compression slits and linear expansion slits in the decorative film, the compression slits extending away from each other in a star shape or in a diamond shape design, the compression slits and the expansion slits penetrating the decorative film in the thickness direction; d') applying the decorative film provided with an adhesive layer onto an adhesive support film to form a sandwich film; e) applying a sandwich film onto the non-planar surface, the sandwich film conforming to convex areas of the non-planar surface by stretching the adhesive support film and the decorative film, and the sandwich film conforming to concave areas of the non-planar surface by compressing the adhesive support film and the decorative film.

[0008] An "essentially rigid" decorative film is understood here not as a rigid decorative film, but rather as a decorative film which in its initial state has limited flexibility and can be bent in one direction, but not simultaneously in two different directions, i.e. around two different axes, and the bendability of the decorative film in its initial state is also limited to larger bending radii and may not permit tight bending radii.

[0009] The application of the respective methods is not limited to wrapping the non-planar surfaces of the vehicle body skin, but can also be applied to almost any three-dimensionally shaped surface, in particular the surfaces present in the interior of a vehicle.

[0010] [effect] The design of the decorative film according to the invention with a pattern of individual slits penetrating the decorative film in the thickness direction means that the decorative film, which is otherwise almost rigid without slits, becomes three-dimensionally flexible due to the slit pattern of the invention. Since the slitting is preferably performed using a laser beam, a cutting plotter or other cutter, the individual slits are very narrow and therefore barely visible when the decorative film is in a flat state.

[0011] In order to ensure that the slit decorative film remains handleable and processable when applied to a non-planar surface, at least one adhesive layer is first applied to the side of the support layer before slitting, which is not slit with the decorative film when it is subsequently slit, and which provides the slit decorative film with the necessary stability for subsequent processing. This adhesive layer is flexible, stretchable, and compressible. The decorative film provided with the adhesive layer can be applied to the adhesive support film before or after slitting. This causes the adhesive layer to adhere to the support film. The support film is also flexible, stretchable, and compressible. If the decorative film is slit after adhering it to the support film, only the decorative film is slit, and the support film remains intact. In this way, a sandwich film is created from the slit decorative film, the adhesive layer, and the support film as a flexible and stretchable film composite. A suitable support film is, for example, a commonly known car wrapping film used for vehicle wrapping.

[0012] The compressed areas of the slitted decorative film can be compressed by a star-shaped or diamond-shaped structure of the slits, which is necessary, for example, when the decorative film must locally fit into a depression or recess in a substrate, such as, for example, a car body skin. In this way, the tapered surface areas of the decorative film remaining between the star-shaped compression slits can converge or overlap to bridge the respective compression slits, so that the decorative film shrinks at this point, i.e. its area is compressed.

[0013] In the expansion region, the decorative film can be stretched transversely, e.g. perpendicularly, to the longitudinal direction of at least one expansion slit, i.e. its area is enlarged, so that the width of such expansion slit increases, at least in its central region.

[0014] The inherent elasticity and compressibility of the adhesive layer and the support film allows them to withstand both the compression of the sandwich film in the compressed areas of the decorative film and the expansion of the sandwich film in the expanded areas of the decorative film.

[0015] A non-planar surface can be curved (curved in two dimensions) or warped (curved in three dimensions) and the curvature can be convex or concave. The convex and concave regions can alternate and the radii of curvature can be different.

[0016] Further preferred and advantageous design features of the method according to the invention form the subject matter of dependent claims 3 to 9.

[0017] A predetermined pattern of compression and expansion slits is preferably cut into the decorative film by a laser beam.

[0018] It may also be advantageous if, after the sandwich film has been applied to the non-planar surface, in a further step e) a protective layer consisting of a transparent protective film or a transparent lacquer layer is applied to the sandwich film.

[0019] A particularly advantageous variant of the method according to the invention, which can be combined with other variants, provides that in order to determine the predefined pattern, first the convex and concave regions of the non-planar surface are identified by means of a CAD program and marked with convex and concave markings, respectively, the non-planar surface thus marked is developed into a plane, the coordinates of the convex and concave markings are transferred to the planar decorative film, the convex markings determining the extension regions into which extension slits are cut and the concave markings determining the compression regions into which compression slits extending away from one another in a star shape or designed in a diamond shape are cut.

[0020] According to a further preferred variant of the method according to the invention, which can be combined with other variants, a first compression zone is provided, in which compression slits extending away from one another in a star shape have a common centre penetrating the decorative film in the thickness direction.

[0021] Furthermore, preferably, second compression zones are provided in which the inner ends of the compression slits extending away from one another in a star shape are spaced apart from one another in the center of the compression element, so that intact areas of the decorative film are formed in the center, in which the decorative film is not cut in the thickness direction. The fact that the centers of these second compression zones are intact means that, if an electrode layer is present, the electrical conduction in the electrode layer of the decorative film, which is configured as, for example, an electronic paper film, is not disturbed in these locations, so that the overall conduction resistance in the respective electrode layer is significantly reduced.

[0022] It is also advantageous that the decorative film provided in step a) is trimmed to a predefined outer contour during or before step a) and then the sandwich film formed in step c) or d') is trimmed to the same outer contour, so that the circumferential cut line for cutting the support film formed is spaced apart from the outer contour line of the decorative film. In this way, it is possible to prevent the periphery of the decorative film from being damaged by trimming the sandwich film along its periphery. This is particularly advantageous when cutting is performed using a laser beam, the intensity of which must be greater for cutting the support film than for cutting the decorative film due to the greater thickness of the support film.

[0023] Preferably, the decorative film has a first electrode layer, a second electrode layer and a decorative layer arranged between the first electrode layer and the second electrode layer, the light reflection or light transmission properties of the decorative layer being changeable by applying a voltage, and the first and second electrode layers of the decorative film provided in step a) are provided with conductive contact tabs during or before step a), each conductive contact tab being preferably pivotable around an axis in the plane of the respective electrode layer.

[0024] An electric current is introduced to the respective electrode layer via these contact tabs in order to bring about a change in the state of the decorative film, which is configured, for example, as an electronic paper film. The pivotability of the contact tabs allows each contact tab to be pivoted out of the plane of the associated electrode layer and led out of a corresponding opening in the non-planar surface that is covered by the sandwich film. In this way, the contacts of the electrode layers are not visible, for example on the vehicle body skin, after the sandwich film has been applied. Alternatively, the contact tabs can be covered with a black, white or colored film or painted.

[0025] Sandwich films applied to non-flat surfaces can be covered with colored films to achieve color effects if desired. Sandwich films applied to non-flat surfaces can also be covered with transparent films or clear lacquers for protection.

[0026] It would be particularly advantageous if the decorative film configured as an electronic paper film works according to the principles of advanced color electronic paper technology, by which any color can be displayed and switched between. In this way, for example, a vehicle used for business purposes and having a specific color for this purpose (e.g. taxi beige, taxi yellow or a company's CI color) can be displayed in a different exterior color for private use.

[0027] Of course, it is also possible and included in the present invention to provide only certain areas of the body skin with decorative film, or to provide different decorative films formed by electronic paper films in different areas of the body skin, so as to enable color switching of smaller segments or molded areas of the body skin. A further idea included in the present invention is to incorporate a flexible active matrix display element as a TFT layer into the sandwich film with the electronic paper film as the decorative film, so that it can display letters and symbols.

[0028] The invention also relates to a sandwich film produced according to the method of the invention, which has a decorative film adhered to a support film by an adhesive layer. The adhesive layer and the support film are flexible, extensible and compressible. By cutting a defined pattern of compressed and expanded regions according to the invention, an initially rather rigid decorative film becomes a flexible, stretchable and compressible decorative film. The sandwich film produced in this way assumes such properties and can be particularly well adapted to the surface profile of non-planar surfaces, such as, for example, the body shell of a vehicle.

[0029] The decorative film advantageously has a plurality of star-shaped compression elements with different numbers of compression slits extending away from each other in a star shape, such a decorative film having regions of varying flexibility and thus being able to conform to substrates having surfaces with different degrees of three-dimensional shaping.

[0030] The smaller the radius of curvature of the convex surface area, the greater the number of expansion elements per unit area in the area of ​​the decorative film that can fit into the convex surface area, which is particularly advantageous.

[0031] It is also particularly advantageous if the radius of curvature of the concave region is smaller, and therefore the number of compression elements per unit area in the region of the decorative film which can be fitted into the concave region is greater.

[0032] The decorative layer of the decorative film is preferably a smart glass LCD layer switchable between transparent and opaque, or an electronic paper layer switchable between two colors, but it can also be, for example, a wood veneer layer.

[0033] The invention also relates to a vehicle, in particular an automobile, having a body skin provided, at least in certain areas, with a sandwich film of such a decorative film, for example in the form of an electronic paper film, by a method according to one of the accompanying claims.

[0034] Preferred embodiments of the present invention, together with additional design details and further advantages, are described in greater detail below with reference to the accompanying drawings. [Brief description of the drawings]

[0035] [Figure 1] FIG. 1 shows a motor vehicle with a body having a body skin. [Diagram 2] FIG. 2 is an enlarged longitudinal cross-sectional view illustrating the structure of an electronic paper display device. [Diagram 3]FIG. 2 shows a three-dimensionally deformed surface section of a decorative film according to the invention, having compressed and expanded regions according to a first embodiment. [Figure 4] FIG. 13 is an enlarged view of a compressed region according to a first modified example. [Diagram 5] FIG. 13 is an enlarged view of an extended region. [Figure 6] FIG. 2 shows in longitudinal cross section a sandwich film produced by the method of the present invention. [Figure 7] FIG. 2 shows a three-dimensionally deformed surface section of a decorative film according to the invention, having compressed and expanded regions according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] 1 shows a motor vehicle 1 having a body 12 with a body skin 10 and an interior 11 at least partially surrounded thereby. In the region of the front bonnet 13 and the front wings 14, 15, as shown diagrammatically by dashed lines, the body skin 10 is wrapped by the method according to the invention with a sandwich film 19 according to the invention, which will be described below. In this region, the body skin 10 forms a non-planar surface 16 with projections 17 and recesses 18.

[0037] 2 is an enlarged longitudinal section showing the structure of an electronic paper film 2' known per se, which forms a decorative film 2 according to the invention. The electronic paper film 2' has a flat, transparent first (upper) electrode layer 20 with a transparent cover layer 21, a flat, transparent second (lower) electrode layer 22 with a support layer 23 and a display layer arranged between the two electrode layers 20, 22, which forms a changeable decorative layer 24.

[0038] The first upper electrode layer 20 is connected to the electrical control device 3 by at least one upper connection tab 29 via a first conductive connection 247, and the second lower electrode layer 22 is also connected to the control device 3 by at least one lower connection tab 29′ via a second conductive connection 248. The control device 3 is supplied with electrical energy by a power source Q. The control device 3 also receives control signals via control lines 30.

[0039] The variable decorative layer 24 of the electronic paper film 2' comprises a plurality of display spheres 240 configured as microcapsules. Each of the display spheres 240 has a transparent housing wall 241 that surrounds an interior 246 of the display sphere 240. The interior 246 contains a plurality of first pigments 242 of a first color (here white) and a plurality of second pigments 244 of a second color (here black) surrounded by a transparent fluid 243, where typically the black pigments 244 are positively charged and the white pigments 242 are negatively charged.

[0040] Upon activating a positive or negative electric field by applying a voltage to the electrodes 20, 22, the black pigment 244 and the white pigment 242 migrate to the respective counter electrodes 20, 22. The amount of pigment particles that migrate to the (transparent) upper electrode 20 is visually perceived by an observer as black or white dots. Further developments of this illustrated electronic paper film 2' with multiple different display spheres containing colored pigments instead of the white pigment 242 can display colors.

[0041] The control device 3 provides electrical switching signals with corresponding polarities to the electrodes 20, 22, for example to switch the display sphere 240 from black to white or vice versa. If the display layer 24 of the electronic paper film 2' can display different colors, the control device 3 can control the display sphere 240 so that the electronic paper film 2' displays a color desired by a user.

[0042] FIG. 3 shows a section of the surface of a decorative film 2 according to the invention, which is provided with a number of compressed regions 4, 4', 4" and extended regions 5, 5', 5". Each compressed region 4, 4', 4" has a star-shaped compressed element 40, 40', 40", shown in detail in FIG. 4, which is formed by a number of compressed slits 42, 43, 44, 45, 46, 47; 42', 43', 44', 45', 46', 47' which extend in a star shape from a common centre 41 and through the decorative film 2 in the thickness direction D. When the decorative film 2 is laid flat as shown in FIG. 4, the compression slits 42, 43, 44, 45, 46, 47; 42', 43', 44', 45', 46', 47' each have a slit width that decreases from the centre 41 of the compression element 40 towards the respective free end of the associated compression slit 42, 43, 44, 45, 46, 47; 42', 43', 44', 45', 46', 47, and thus each compression slit 42, 43, 44, 45, 46, 47; 42', 43', 44', 45', 46', 47' tapers towards its free end.

[0043] Adjacent compression elements 40, 40' each form a pair of compression slits 42, 42' converging towards each other. The free ends of these converging compression slits 42, 42' do not contact each other and are spaced apart, leaving between them a slit-free bridge region 48 in which the decorative film 2 is intact and thus electrically functional in the case of the electronic paper film 2'. These converging compression slits 42, 42' have a common central axis M in their longitudinal extension.

[0044] The expansion elements 50 forming the expansion regions 5 are always provided between two adjacent compression elements 40, 40'. For this purpose, a first expansion slit 52 and a second expansion slit 54 aligned parallel to each other extend parallel to each pair of converging compression slits 42, 42' and are spaced apart laterally on two oppositely facing sides of the pair of converging compression slits 42, 42', as shown in Fig. 5. When the decorative film 2 is laid flat, each expansion slit 52, 54 has longitudinal edges parallel to each other and therefore has a constant slit width, as shown in Fig. 5.

[0045] The extended slits 52, 54 also penetrate the decorative film 2 in the thickness direction D. Thus, in the case of the electronic paper film 2', the compression slits 42, 43, 44, 45, 46, 47; 42', 43', 44', 45', 46', 47' and the extended slits 52, 54 are all cut locally through the cover layer 21, the first electrode layer 20, the display layer 24, the second electrode layer 22 and the support layer 23.

[0046] The expansion slits 52, 54 running parallel to the common central axis M of the compression slits 42, 42' extend towards their free ends up to the front third or half of the longitudinal extension of the associated compression slit 42, 42' respectively.

[0047] When a tensile force acting transversely, for example perpendicularly, to the longitudinal extension of the extended slits 52, 54 is applied to the decorative film 2 on the film surface (as symbolically shown by arrow E in Figure 5), the opening width of the extended slits 52, 54, i.e., their expansion, increases and the decorative film 2 in this region stretches locally transversely to its longitudinal extension along the common central axis M.

[0048] When a compressive or shear force acting towards the center 41 of the compression element 40 (symbolically shown by arrow K in Figure 4) is applied to the decorative film 2 on the film surface, the opening width of at least one compression slit 42, 42' is reduced and thus the decorative film 2 is locally compressed in this area.

[0049] 6 shows a longitudinal section through a sandwich film 19 produced by the method of the invention. The decorative film configured as an electronic paper film 2' has a transparent upper electrode layer 20 electrically conductively connected to the electrical control device 3 and provided with a transparent cover layer 21, a lower electrode layer 22 also conductively connected to the electrical control device 3 and provided on a support layer 23, and a display layer 24 located therebetween.

[0050] The support layer 23 is provided with an adhesive layer 26 on its lower surface facing the lower electrode layer 22. The adhesive layer 26 is formed, for example, by a thin double-sided adhesive film 25, but can also be formed by a film of adhesive applied to the support layer 23 by spraying. The electronic paper film 2' thus provided with the adhesive layer 26 is then laminated onto an adhesive support film 27, formed, for example, by a flexible, extensible and compressible car wrapping film 28, so that an initially not very flexible but rather rigid film composite is created as a sandwich film. This film composite is then subjected to a laser cutting process, in which the electronic paper film 2' is cut from its upper side, i.e. from the side with the cover layer 21, using a laser beam to form a predetermined pattern of slits, compression slits 42 and expansion slits 52, illustrated in FIG. 6. The adhesive layer 26 and the support film 27 remain intact, but the cutting imparts flexibility, local extensibility and local compressibility to the decorative film 2 formed by the electronic paper film 2'.

[0051] Fig. 7 shows a modified embodiment of a decorative film 102 designed according to the present invention and formed as an electronic paper film 102', which in principle corresponds to the decorative film 2 of Fig. 3. As in the decorative film 2 configured as an electronic paper film 2', electrical connection tabs 29, 29' are provided on the upper electrode layer 20 and on the lower electrode layer 22, via which electrical energy is introduced to the electrode layers 20, 22 of the electronic paper film 102'. As a variation of the embodiment of FIG. 3, the electronic paper film 102' shown in FIG. 7 not only has compressed regions 4, 4', 4" having star-shaped compressed elements 40, 40', 40" whose compression slits meet at a common center 41, but also has compressed regions 104, 104', 104", 104"', 104"" in which star-shaped compressed slits 141, 141', 141", 141"', 141"" have star-shaped compressed elements 140, 140', 140", 140"', 140"" that are not connected to each other at the center of the respective compression elements 140, 140', 140", 140"', 140"". As a result, the electronic paper film 102' remains intact and undamaged in its respective centers 141, 141', 141", and current can flow unimpeded through the respective compression elements 140, 140', 140", 140"', 140"" with little resistance in these central regions. In this way, power supply to the compression elements 40, 40', 40", which are further away from the connecting lugs 29, 29', is improved.

[0052] The invention is not limited to the above exemplary embodiments, which serve only to generally illustrate the central idea of ​​the invention. Within the scope of protection, the device according to the invention can also envisage other embodiments than those described above. This device can have the features, in particular those that represent combinations of the respective individual features of the claims.

[0053] Reference numbers in the claims, the description and the drawings are intended only to facilitate understanding of the invention and are not intended to limit the scope of protection. [Explanation of symbols]

[0054] 1. Automobile (Kraftfahrzeug) 2 Decorative film (Dekorfolie) 2' E-Paper-Folie 3 Control device 4 Compression Area 4' Compression region 4” Compression Area 5 Expansion Areas 5' extension region 5” extended open area 10 Car body shell 11 Inside the train (Fahrzeuginnenraum) 12 Vehicle body (Fahrzeugkarosserie) 13 Bonnet (Haube) 14 Wing (Kotfluegel) 15 Wing 16 Non-planar surfaces (nicht-ebene Oberflaeche) 17 Convex part of 10 18 Concave part of 10 19 Sandwich-Folie 20 Flat and transparent first (upper) electrode layer 21 Cover layer (Deckschicht) 22 Flat and transparent second (lower) electrode layer 23 Supporters (Traegerschicht) 24 Decorative layer 25 Adhesive film (Klebefolie) 26 Adhesive layer 27 Support film (Traegerfolie) 28 Car Wrapping Film 29 Connection tab (Anschlussfahne) 29' Connection tab 30 Control lines 40 Compression element 40' Compression Element 40” compression element 41 Center (Zentrum) 42 Compression slit 42' compression slit 43 Compression Slit 43' compression slit 44 Compression Slit 44 Compression Slit 45 Compression Slit 45' compression slit 46 Compression Slit 46' compression slit 47 Compression Slit 47' compression slit 48 Bridge area without slits 50 Expansion elements 52 Expansion slit 54 Expanded Slit 102 Decorative film (Dekorfolie) 102' E-Paper-Folie 104 Compression Area 104' Compression Region 104” Compression Area 104"' Compression Region 104"" Compression Area 140 Compression element 140' compression element 140” compression element 140" compression element 140” compression element 141 Center (Zentrum) 141' center 141” center 141”' center 141”” center 240 Display sphere (Anzeigekugel) 241 Transparent housing wall 242 First Pigment 243 Transparent Fluid 244 Secondary pigment (zweite pigment) 246 Interior Space (Innenraum) 247 First Electrical Conductive Connection 248 Second electrically conductive connection D thickness direction (Dickenrichtung) E Arrow (Extension) (Pfeil (Dehnung)) K Arrow (Compression) (Pfeil (Stauchung)) M center line (Mittelachse) Q Power supply (elektrische Stromquelle)

Claims

1. A method for applying an essentially rigid decorative film (2) having a decorative layer (24) onto a non-planar surface (16), preferably the body skin (10) of an automobile (1), comprising the steps of: a) providing said decorative film (2); b) applying an adhesive layer (26) onto said decorative film (2); c) applying said decorative film (2) provided with said adhesive layer (26) onto an adhesive support film (27) to form a sandwich film (19); d) cutting a predetermined pattern of compression slits (42, 43, 44, 45, 46, 47; 42', 43', 44', 45', 46', 47') and linear expansion slits (52, 54) in the decorative film, the compression slits extending away from each other in a star shape or in a diamond shape design, the compression slits (42, 43, 44, 45, 46, 47; 42', 43', 44', 45', 46', 47') and the expansion slits (52, 54) passing through the decorative film (2) in a thickness direction (D); e) applying the sandwich film (19) onto the non-planar surface (16), the sandwich film (19) conforming to the convex areas (17) of the non-planar surface (16) by stretching the adhesive support film (27) and the decorative film (2) and the sandwich film (19) conforming to the concave areas (18) of the non-planar surface (16) by compressing the adhesive support film (27) and the decorative film (2); A method comprising:

2. A method for applying an essentially rigid decorative film (2) having a decorative layer (24) onto a non-planar surface (16), preferably an outer body skin (10) of an automobile (1), comprising the steps of: a) providing said decorative film (2); b) applying an adhesive layer (26) onto said decorative film (2); c') cutting a predetermined pattern of compression slits (42, 43, 44, 45, 46, 47; 42', 43', 44', 45', 46', 47') and linear expansion slits (52, 54) in the electronic paper film (2), the compression slits are designed to extend away from each other in a star shape or a diamond shape, and the compression slits (42, 43, 44, 45, 46, 47; 42', 43', 44', 45', 46', 47') and the expansion slits (52, 54) penetrate the decorative film (2) in a thickness direction (D); d') applying said decorative film (2) provided with said adhesive layer (26) onto an adhesive support film (27) to form a sandwich film (19); e) applying the sandwich film (19) onto the non-planar surface (16), the sandwich film (19) conforming to the convex areas (17) of the non-planar surface (16) by stretching the adhesive support film (27) and the decorative film (2) and the sandwich film (19) conforming to the concave areas (18) of the non-planar surface (16) by compressing the adhesive support film (27) and the decorative film (2); A method comprising:

3. cutting the predetermined pattern of the compression slits (42, 43, 44, 45, 46, 47; 42', 43', 44', 45', 46', 47') and the expansion slits (52, 54) into the decorative film (2) by a laser beam; 3. The method according to claim 1 or 2.

4. After application of the sandwich film (19) to the non-planar surface (16), in a further step e) a protective layer consisting of a transparent protective film or a transparent lacquer layer is applied to the sandwich film (19), 4. The method according to claim 1 ,

5. To determine the predetermined pattern, first, the convex and concave areas of the non-planar surface (16) are identified by a CAD program and marked with convex and concave markings, respectively; The non-planar surface (16) thus marked is then developed into a plane; Transferring the coordinates of the convex markings and the concave markings to the planar decorative layer (2), said convex markings define the extension areas (5, 5') in which said extension slits (52, 54) are cut; said concave markings determine the compression areas (4, 4', 4"; 104, 104', 104", 104"', 104"") in which the compression slits (42, 43, 44, 45, 46, 47; 42', 43', 44', 45', 46', 47') are cut, which extend away from each other in a star shape or are designed in a diamond shape, 5. The method according to any one of claims 1 to 4.

6. a first compression zone (4, 4', 4") is provided, in which the compression slits (42, 43, 44, 45, 46, 47; 42', 43', 44', 45', 46', 47') extending away from each other in a star shape have a common center (41) passing through the decorative film (2) in a thickness direction (D); 6. The method according to any one of claims 1 to 5.

7. a second compression zone (104, 104', 104", 104'", 104"") is provided, in which the inner ends of the compression slits extending away from each other in a star shape are spaced apart from each other at a center (141, 141', 141", 141"", 141"") of the compression element (140, 140', 140", 140"", 140""), thus forming an intact area of ​​the decorative film at the center, where the decorative film has not been cut through its thickness; 7. The method according to any one of claims 1 to 6.

8. Trimming said decorative film (2) provided in step a) to a predetermined outer contour shape during or before step a), Thereafter, the sandwich film (19) formed in step c) or d') is trimmed to the same outer contour shape, the cutting line cutting through the support film (27) being spaced apart from the outer contour of the decorative film (2), 8. The method according to any one of claims 1 to 7.

9. The decorative film (2) has a first electrode layer (20), a second electrode layer (22), and a decorative layer (24) disposed between the first electrode layer and the second electrode layer, The light reflection or transmission characteristics of the decorative layer can be changed by applying a voltage; the first electrode layer (20) and the second electrode layer (22) of the decorative film (2) provided in step a) are provided, during or before step a), with conductive contact tabs (29, 29'), each conductive contact tab being preferably pivotable about an axis that lies in the plane of the respective electrode layer (20, 22); 9. The method according to any one of claims 1 to 8.

10. 10. A sandwich film (19) having the decorative film (2) adhered to a support film (25) by means of the adhesive layer (26), the sandwich film being produced by a method according to any one of claims 1 to 9.

11. 10. A vehicle (1), in particular an automobile, having at least one surface, said surface having non-planar areas and wherein the sandwich film (19) with the decorative film (2) is applied at least in certain areas by the method according to any one of claims 1 to 9.

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