Method for producing a decorative element and use of the decorative element

Abstract

To provide a method for producing a decorative element DE and the use of the decorative element DE produced in such a way.SOLUTION: A polarizing layer PS functioning as an analyser is applied to a transparent optical carrier material TM, and a transparent optical functional layer FS is applied to the other side as an image forming layer BS consisting of an optically anisotropic material OAM. The dependence depending on a target position in material properties of the optically anisotropic material OAM is generated by spatially structuring the functional layer FS by an image forming method, in order to generate the image forming layer BS in the form of an image motif BM. One or more decorative elements DE produced according to the present invention are introduced into an optical field of an illumination device BV in a desired form, size and quantity, each have the settable image motif BM (image structure), are arranged at different spatial distances and can be arranged freely.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing a decorative element and to the use of the decorative element thus produced. [Background technology]

[0002] Decorative elements are known that have the properties of displaying specific graphic, visual or textual designs and that certain colors, paints, substances or coatings, which are generally produced using specific substance-based color pigments (dyes), are commonly used to design the respective decorative surfaces.

[0003] Likewise, special pigments are known which have additional optical effects beyond the actual color value, with which particularly corresponding decorative elements can also be produced.

[0004] It is known that decorative coatings have specific optical effects, for example at different viewing angles or with respect to their reflection behavior.For the production of corresponding decorative elements and decorative design, a large number of effect pigments are used, in particular specific interference pigments, multilayer pigments, metallic effect pigments or goniochromatic pigments.These so-called luster or effect pigments with specific interference phenomena are therefore very widely used, for example for automotive paints, all kinds of decorative coatings, as well as for coloring plastics, paints and inks.

[0005] EP 0 727 472 A1 describes effect paints, especially for automobile bodies, in which the optical effect consists of so-called color flops, by means of which a changing color impression appears depending on the incidence of light (goniochromatic pigments).

[0006] EP1624030A2 shows metallic effect pigments with silver as well as colour-neutral pigment mixtures using two different pigments, a weakly coloured silver interference pigment and a weakly coloured interference pigment of the complementary colour.

[0007] EP 1 620 511 A2 describes interference pigments which have a high covering power and which comprise platelet-shaped inorganic substrates and have a layer containing FeTiO3.

[0008] US Pat. No. 8,500,901 B2 discloses interference pigments based on a flake-shaped substrate and consisting of layers with high or low refractive index.

[0009] The abovementioned decorative elements are produced with the aid of certain known decorative colours, paints or coatings. For this purpose, certain colour pigments are invariably used, whereby the production of the respective colouring and the production of the decorative patterns is in each case based on one particular substance base and the respective colour of these pigments.

[0010] In the special case of effect pigments, this makes it possible to generate additional optical effects specific to the decorative element in addition to the respective color, which are essentially based on the known fundamental optical effects of interference phenomena in thin layers, however these effects, such as goniochromatic effects, only show a limited appearance to a few effects, such as color flop effects.

[0011] All known decorative elements or decorative surfaces are disadvantageous in the sense that, on the one hand, the selected motif or decoration including its optical image remains permanently visible and, on the other hand, the respective appearance is not instantly changeable in a targeted manner.

[0012] This drawback is ultimately due to the fact that in the manufacturing process of the decorative elements, known color pigments or color particles based on specific substances are applied which appear essentially permanent.

[0013] The display of optical effects in association with suitable lighting devices is also known.

[0014] EP2499538B1 shows a system in which a lighting device with dynamically controllable light modulation functionality generates photo-optical effects in combination with a display object as a projection surface.

[0015] However, such systems are relatively complex devices due to the dynamic interaction between the light modulating lighting devices and the displayed objects. Summary of the Invention [Problem to be solved by the invention]

[0016] It is therefore an object of the present invention to propose a method for producing a decorative element, whereby no material-based color pigments are used and whereby the produced decorative element serves for producing, displaying and modifying configurable color graphic motifs in connection with a suitable lighting device. [Means for solving the problem]

[0017] This object is achieved by a manufacturing method comprising the steps of providing a transparent optical carrier material TM having a flat or curved surface and consisting of a glass or plastic substrate, applying a polarizing layer PS acting as an analyzer to one side of the carrier material TM, applying a transparent optical functional layer FS as an image-forming layer BS consisting of an optically anisotropic material OAM having a layer thickness to the other side of the carrier material TM, and structuring the functional layer FS image-forming spatially by a target-position-dependent dependence on the material properties of the optically anisotropic material OAM to generate the image-forming layer BS in the form of an image motif BM, so that a settable color contrast with a polarized interference color PIF determined according to the image motif BM is visible on the illuminated surface of the decorative element DE by illumination with polarized light.

[0018] A polarizing layer PS, which acts as an analyzer, is first applied to a lateral side of a transparent optical carrier material TM, which consists of a glass or plastic substrate with a flat or curved surface. On the other side, a transparent optically functional layer FS, which has a specific layer thickness and serves as an image-forming layer BS, which consists of an optically anisotropic material OAM, is applied to the carrier material TM.

[0019] Advantageously, the decorative element DE may be formed in any shape, for example a flat object having a plane or curved shape, or a profiled surface element, or a tangible object.

[0020] In the next step to generate an image-forming layer BS in the form of an image motif BM by spatially structuring the functional layer FS in an image-forming manner, a target position-dependent dependence in the material properties of the optically anisotropic material OAM is generated.

[0021] Furthermore, the image-forming layer BS can include, for example, patterns, fonts or motifs having a virtually unlimited number of hues, each with a desired color palette and different color intensities and color contrasts, which can be used for flexible design purposes.

[0022] In this way, an alternative method for the color design of artistic or graphic surfaces in decorative elements DE is presented, during the production of which no material-based color pigments are used, but instead the decoration is achieved in a purely physical way by using in conjunction with a suitable lighting device BV. To manufacture a decorative element DE, which makes it possible to create and design a multi-colored color contrast in the element DE, a simple and uncomplicated method is applied, from which, according to the invention, specific transparent materials having specific properties, structure and arrangement are used.

[0023] According to the method according to the invention, the decorative element DE consists of suitable passive materials in a specific arrangement, which in connection with being illuminated according to the method therefore has specific new light-optical functions, only in this case the respective color graphic design of the otherwise potential motifs is visually manifested, whereas the optical phenomena become invisible when the decorative element DE is illuminated by natural or other common artificial light sources.

[0024] The optically functional layer FS, made of a passive material and included in the decorative element DE, is further characterized by specific internal material properties defined according to the invention and having specific material properties in the form of a defined optical anisotropy, which further enables a settable latent image motif BM to be imprinted due to a local change or modification of this material property.

[0025] Additionally, passive materials are advantageous in that they are inexpensively available and easily mass-produced; they are characterized by simplicity, robustness, and the applicability of common processing and assembly techniques such that they can be conveniently manufactured using multiple materials, shapes, and profiles with a variety of surface properties and compositions.

[0026] In a further embodiment, a transmissive polarizing layer PSt is used as the polarizing layer PS for producing an illuminating decorative element DE or a reflective polarizing layer PSr is used as the polarizing layer PS for producing a reflective decorative element DE.

[0027] Thus, a transparent decorative element DE having a transparent polarizing layer PSt on the observer side can be advantageously used, for example, in transparent window elements, which may each have a specific arrangement that can also include a corresponding backlight.

[0028] On the other hand, a reflective decorative element DE resulting in a reflective polarizing layer PSr can be advantageously used for all non-transparent architectural or design elements (see below), said reflective polarizing layer PSr being arranged behind the image-forming layer BS so that light hitting the decorative element DE is reflected in the direction of the observer.

[0029] Advantageously, the target position dependent dependence in the material properties of the optically anisotropic material OAM is brought about by local changes in one or more of: a) a change in optical anisotropy; b) a change in layer thickness; c) a change in local configuration.

[0030] The spatial structuring of the optically anisotropic material OAM, and thus the production of image motifs BM by position-dependent changes in the material properties, can thus be brought about by influencing the optical anisotropy, the layer thickness or the local orientation.

[0031] Furthermore, a local optical path difference LOG, which can be set in a defined manner, is realized by a dependency on the material properties of the optically anisotropic material OAM depending on the target position, each value of the local optical path difference LOG corresponding to one defined polarized interference color PIF imprinting the image motif BM.

[0032] This imprinting of the respective image information is based on the use and targeted modification of specific material properties of the functional layer FS for generating the image-forming layer BS, in particular an optically anisotropic material OAM having a specific, locally defined optical anisotropy is used, whereby an image motif BM is generated in the sense of a so-called phase image, whereby this image information is represented by the image motif BM. It is based on a correspondingly addressed local optical path difference LOG in the sense of an image motif BM, whereby a corresponding local color contrast can be generated according to the polarization interference color PIF resulting from the value of the local optical path difference LOG.

[0033] The color values ​​expected based on each value of the local optical path difference LOG are shown, for example, by a Levy interference color chart, and the assignment between each value of the optical anisotropy or local optical path difference LOG and each color is shown.

[0034] This correlation can be advantageous for the design of the image motif BM, since the Lévy color chart makes it possible to determine in advance the local optical path differences LOG required to produce a desired color palette and can therefore be used to design each color contrast individually.

[0035] The targeted, locally addressable imprint of a particular local optical path difference LOG, in the sense of a configurable image motif BM in the imaging layer BS, can be caused by various means and methods.

[0036] For example, certain transparent plastic materials (such as polycarbonate) or certain axially oriented film materials (such as BOPP) or corresponding materials based on liquid crystals (such as reactive mesogens RM) can be used in the sense of the method according to the invention.

[0037] Advantageously, the local optical path difference LOG is realised in such a way that it has a specific, settable, constant value over the entire surface or over a defined portion of the surface of the decorative element DE.

[0038] Preferably, the local optical path difference LOG is realized in a uniform manner for the defined portion of the surface of the decorative element DE and the settable constant value is close to zero, whereby each of the polarized interference colors PIF is generated achromatically for the uniform surface of the decorative element DE.

[0039] The decorative element DE thus appears to have only one specific uniform brightness, the respective degree of brightness depending on the relative arrangement of the orientation of the polarizing layer PS with respect to the polarization direction of the illumination, so that, when the relative polarization direction is changed accordingly, maximally brightened local areas produce the color impression white, while in the case of correspondingly dimmed local areas each grey value up to black is perceived.

[0040] Furthermore, to form the functional layer FS, an alignment layer OS is first applied to the carrier material TM and a liquid crystal based LC material LC is applied on top as optically anisotropic material OAM.

[0041] In connection with the manufacture of the image-forming layer BS and the color graphic design, preferably materials are used which are based on liquid crystals and have a specific optical anisotropy themselves, and means are used to cause a structuring of the local optical anisotropy and / or layer thickness and / or alignment which can be addressed in a targeted manner, whereby each value of the local optical path difference LOG can be imprinted into a specific, settable graphic shape according to a settable image motif BM.

[0042] For example, a reactive mesogen RM can be used to generate an LC layer LC, which in turn generates a correspondingly graphically structured image-forming layer BS having a local optical path difference LOG that can be addressed in a targeted manner.

[0043] By various methods, an alignment layer which defines the respective optical axis and which is generally applied to a transparent carrier material TM is generally realised first, thereby also defining the optical axis of the subsequently applied reactive mesogens RM according to the desired structuring, after which the respective mesogenic layers are also oriented accordingly and subsequently cured (e.g. UV curing).

[0044] In a first step, for example, a correspondingly structured orientation layer OS is first produced in a suitable transparent carrier material TM. For this, various available orientation methods (for example photoalignment by specific photolithographic methods using a corresponding mask) can be used, and the respective optical axes of each selected anisotropic region can be aligned in a targeted manner. This orientation, which can be set in the corresponding regions, is then transferred to the LC layer LC, which is coated in a subsequent step, for example in the form of a mesogenic layer.

[0045] The image-forming layer BS can then also be applied to several layer sequences by means of an alignment layer associated with each LC layer LC in the form of a reactive mesogen RM with a configurable graphic structure and by various methods, thereby generating the values ​​required to generate the image-forming layer BS for the local optical path difference LOG resulting respectively from each layer structure, which then represents the latent image motif BM.

[0046] Preferably, the LC material LC is applied by a coating technique followed by curing or by a printing technique.

[0047] Exemplary techniques include slot die coating or Mayer rod coating.

[0048] Instead of applying the LC material LC, a film material FO may be applied as the optically anisotropic material OAM to form the functional layer FS.

[0049] To produce the image-forming layer BS, a film material FO is used, which is commercially available in the form of a corresponding customized plastic film (e.g. axially stretched films such as Oracal Film from ORAFOL or BOPP), which already has a specific internal optical anisotropy and can therefore be used for the production and design of the image-forming layer BS according to the invention, and which can then be utilized for graphic image design and / or specially modified by corresponding targeted follow-up processing, so as to achieve the local optical path difference LOG of the graphic structure desired in each case.

[0050] Said film material FO is preferably applied by lamination.

[0051] By means of a lamination process the film material FO can be connected in a simple manner to the carrier material TM.

[0052] Advantageously, a targeted spatial structure birefringence is induced in the film material F by suitable processing means, or an existing intrinsic optical anisotropy in the film material FO is utilized to generate an image motif BM, and / or follow-up processing is provided in a targeted manner.

[0053] A suitable follow-up treatment could for example be a controlled, locally addressable change of the optical anisotropy values ​​in each film material FO. It is also conceivable to completely remove the anisotropy and convert the corresponding image regions into correspondingly located isotropic regions, followed by forming a corresponding contrast for the image regions still having the corresponding anisotropy, whereby the graphic structures according to the image stand out accordingly from the background.

[0054] Also advantageous is a very simple follow-up processing of the film material FO aimed at subsequently causing targeted, localized removal of the inherent optical anisotropy present in each film material FO, thereby allowing each contrast to be generated in the sense of motif production and graphic design, and each negative image motif NBM, which itself has a specific value of the local optical path difference LOG, meaning the local optical anisotropy associated with each image motif BM, can be cut from the film material FO using suitable tools such as a cutting plotter, a laser cutter or a water jet cutter.

[0055] Advantageously, a number of transparent optical functional layers FSi are applied as image forming layers BSi having different image motifs BMi, superimposed on one another in a defined manner to form a composite material V, and bonded to the resulting interactive optical functional layer FSr to generate a resulting effective local optical path difference LOGr for said composite material V.

[0056] When combined into a composite material, each different image-forming layer BSi may have a different, configurable layer thickness, alignment, orientation and position corresponding to a particular layer sequence, thus resulting in a respective effective local optical path difference LOGr for the resulting optically functional layer FSr combined into the composite material.

[0057] In this way, highly complex multi-form and corresponding multi-colored color graphic image motifs BM can be generated, including a correspondingly extended color palette and a corresponding number of different color contrasts in the polarized interference color PIF, whereby the corresponding image motifs BM with their color compositions can be designed accordingly.

[0058] For example, specific modifications of the alignment in the cross section of the image-forming layer BS provide additional design options for each color value, which can be utilized in particular when using optically anisotropic foil materials FO and is particularly advantageous when using several laminated films (see below), where additional design options for the resulting color values ​​are made possible by additional modifications of each alignment in the cross section or in each layer.

[0059] Advantageously, if the optically anisotropic material OAM is realised as a film material FO, a number of film layers FOi are applied to the carrier material TM as a stack.

[0060] Such an arrangement of a number of film layers FOi superimposed on one another in a specific manner in the stacked decorative element DE may be arranged in a specific manner such that each individual film layer FOi has a specific image-forming layer Bsi which contains at this point an image motif BMi, and these film layers FOi are specifically laminated with another film layer FOi or with several film layers FOi simultaneously at a defined partial surface, so that in this way a value of the resulting effective local optical path difference LOGr is determined, which is then constructed from the respective position-specific superpositions and then with the resulting global image motif BMr.

[0061] An additional measure for the graphic design of the image motif BMi may be the respective alignment of each film layer FOi, which is used in a desired arrangement and overlap, and each anisotropic film layer FOi has a pre-existing alignment in a specific preferred direction. In this context, a corresponding angle rotated orientation is arranged for each film layer FOi, or for a specific section of a film layer FOi, whereby each local optical path difference LOGi and thus the color contrast of each resulting polarization interference color PIFi are targeted and adjusted according to their respective orientations relative to each other. Illustratively, the retardance value increases when normally aligned, while when rotated 90 degrees the retardance value decreases accordingly.

[0062] Furthermore, the individual film layers FOi may extend over specific defined local areas and each may have different defined recesses and / or cutouts that may be set based on each of the motifs.

[0063] Thus, different film layers FOi partially overlap each other in various ways, and several different layers in the various image-forming layers BSi are realized by said film layers FOi, which can be used as a composite material, each with their own configurable film thickness, alignment, orientation and configuration.

[0064] The shared effective local optical path difference LOGr results from the interaction and superposition of the individual local optical path differences LOGi.

[0065] Furthermore, the object of the invention is achieved by using a decorative element manufactured according to the invention in the following manner: photo-optical effects are generated and influenced in a targeted manner exclusively via the light path in interaction with an external lighting device BV emitting unpolarized or polarized light with a variable polarization direction, and the following operating modes are realized: a) neutral mode NM: the decorative element DE has no polarized interference color PIF when illuminated with unpolarized light, and therefore the latent color graphic motif FM in the image-forming layer BS remains in principle invisible, b) presence mode PM: the decorative element DE is illuminated with polarized light, and the color graphic motif FM is visibly displayed according to the defined polarized interference color PIF, c) color variation mode FVM: a defined stepless color variation is possible in the color variation mode FVM by the defined polarized interference color PIF in the color graphic motif FM, and the latent color graphic motif FM in the image-forming layer BS remains in principle invisible, b) presence mode PM: the decorative element DE is illuminated with polarized light, and the latent color graphic motif FM in the image-forming layer BS remains in principle invisible, c) color variation mode FVM: a defined stepless color variation is possible in the color variation mode FVM by the defined polarized interference color PIF in the color graphic motif FM, and the latent color graphic motif FM in the image-forming layer BS remains in principle invisible, Color variations is caused by a change in the polarization direction of the polarized light.

[0066] One or more decorative elements DE manufactured according to the present invention can be introduced into the light field of the lighting device BV in any desired shape, size and quantity, each having a configurable image motif BM (image structure), positioned at different spatial distances and freely disposable.

[0067] Furthermore, the lighting device BV allows a change between unpolarized or polarized light and a targeted variation of the polarization direction to correspond to the lighting conditions, in contrast to the isotropic light field appearing in the case of unpolarized light, in which no image structures are displayed (neutral mode NM). When the decorative element DE is illuminated with polarized light, the latent image structures contained in the image-forming layer BS become visible as corresponding graphic image motifs BM in a corresponding color contrast (presence mode PM).

[0068] In addition, by changing the polarization direction, the polarization and interference colors PF contained in each image motif BM can be changed in the same sense (color variation mode FVM).

[0069] The environment of the decorative element DE, or of a particular object or item that is also illuminated by polarized light, appears completely unchanged.

[0070] A special feature of illumination with polarized light according to the invention is that polarized light exhibits very special light properties that are not perceptible to the naked eye, and therefore the difference between polarized light and unpolarized light is not noticeable.

[0071] Therefore, the quality and brightness of light observed by the naked eye remains unchanged in all cases when switching between unpolarized and polarized light, and when changing the polarization direction. Therefore, it is no different from normal lighting using lamp light.

[0072] Apart from the above-mentioned special optical properties for the lighting part, the optical-optical function is also based on additional special features in the material properties of the image-forming layer used in this case in the decorative element DE, which, due to the completely transparent material properties, in normal lighting conditions, generally without polarized light, structures which are not visible even in this material, in the case of optically anisotropic, optically anisotropic materials also appear continuously transparent and the correspondingly structured polarized interference color PIF is only visible when illuminated with polarized light.

[0073] The spatial separation between the lighting device BV and the freely positionable decorative element DE is advantageous in that, depending on the embodiment and the arrangement, the decorative element DE can be used in transmitted light in a transmissive case or in reflected light in a reflective case.

[0074] Moreover, it is advantageous that the decorative elements DE produced according to the invention, meaning each decorative element DE itself, contains a specific latent image motif BM, which in this case exists in the form of specific optical material properties and has a real material internal spatial structure. Therefore, the arrangement of any number of decorative elements DE, all illuminated by respective light sources, is therefore fundamentally different from a common image projection.

[0075] This is because each decorative element DE formed and individually differently sized can be jointly illuminated by a single light source (lighting device BV) together with a specified number of additional decorative elements DE in the desired spatial arrangement and each having a different spatial depth, each decorative element DE can separately have a different image motif BMi, and all decorative elements DE can be moved arbitrarily in each of these spatial arrangements.

[0076] In contrast, conventional image projection always requires specific imaging optics and a corresponding screen, where each single image projected from only one projector can be sharply depicted at only one single image plane with a set spatial depth, and each image from the projection can be focused only with respect to a single defined distance from the screen.

[0077] Furthermore, the decorative element DE advantageously consists only of passive materials and therefore does not contain any moving parts or electronic elements and does not require any power supply from electrical wires.

[0078] Nevertheless, actively controllable variation of the respective optical appearance can be carried out in an invisible manner exclusively via the light path in these passive decorative elements DE, which allows free selection of specific operating modes on the lighting parts, such as, for example, the visibility of the image motif BM in the case of the presence mode PM or its invisibility in the case of the neutral mode NM and the variation of the color contrast in the case of the color variation mode FVM.

[0079] The selection and implementation of the operating modes (neutral mode NM, presence mode PM and color variation mode FVM) in the lighting device BV is performed by adjustment means M realized by a polarizing filter PF and its respective position in the optical path of the illumination.

[0080] Preferably, the selection and implementation of a particular operating mode by the adjustment means M is performed a) for the neutral mode NM by removing the polarizing filter PF from the optical path, b) for the presence mode PM by introducing the polarizing filter PF into the optical path, and c) for the color variation mode FVM by appropriately rotating the polarizing filter PF, and the neutral mode NM It is possible to arbitrarily switch between disappearance in the presence mode PM, visibility in the presence mode PM, and the color variation in the color variation mode FVM.

[0081] Furthermore, from the point of view of the device, the decorative element produced according to the invention is intended to be used as an architectural element for producing light-optical effects in the exterior areas of buildings or as a design element for interior design or object design.

[0082] For example, use as part of a facade, a wall covering, a ceiling element, a floor covering or as part of various design objects such as furniture, lamps or general installation objects seems possible.

[0083] In particular, the embodiment of the decoration element DE as a sign-bearing element is advantageous.

[0084] The decorative elements DE produced according to the invention can be used as sign-bearing elements, such as for optical guidance systems, or as image-bearing and text-bearing elements for advertising spaces.

[0085] Furthermore, the use of said decorative element DE is advantageous if the mechanical processing, cutting or suitable customization of said decorative element made of purely passive material is realized with common tools.

[0086] From the apparatus point of view, a further use of a decorative element DE manufactured according to the invention comprises a reflective polarizing layer PSr and a local optical path difference LOG having a constant value that can be set near zero, said decorative element DE being arranged as a background surface H on which an object O to be displayed is presented, said object O and said background surface H being jointly illuminated by a lighting device BV, so that, when the luminous intensity in the light field LF containing both the object O and the background H does not change, only the luminance of the background surface H is steplessly dimmable, while the luminance of the jointly illuminated object O remains unchanged by changing the polarization direction of the lighting device BV.

[0087] Further advantageous features can be derived from the following description and drawings which explain preferred embodiments of the invention by way of example. [Brief description of the drawings]

[0088] [Figure 1] FIG. 1 shows the schematic structure of a decorative element DE produced according to the invention. [Diagram 2] FIG. 2 shows a schematic layout of the lighting device BV. [Diagram 3] FIG. 3 shows a schematic diagram of an imaging layer BS offset at an angle and a triple superposition of three imaging layers BS1, BS2, BS3. [Figure 4] FIG. 4 shows a schematic diagram of two overlapping imaging layers BSi. [Diagram 5] FIG. 5 shows an example of use with an object O placed in a decorative element DE. [Figure 6] FIG. 6 shows a schematic diagram of a method for producing a decorative element DE based on a LC material LC. [Figure 7] FIG. 7 shows an example of the use of a decorative element DE having two film layers FOi. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0089] FIG. 1 shows the schematic design of a decorative element DE having an image-forming layer BS, a carrier layer TM, a polarizing layer PS and a functional layer FS, the image-forming layer BS being present in the form of a local optical path difference LOG, whereby a respective polarized interference color PIF appears according to an image motif BM.

[0090] FIG. 2 shows a schematic arrangement of an illumination device BV consisting of a light source L and a polarizing filter PF that is variable in terms of polarization direction, the illumination device BV emitting polarized light PL.

[0091] Figure 3 shows a schematic diagram of an image-forming layer BS constituting an image motif BM and the superposition of three identical image-forming layers BS1, BS2, BS3 having the same image motif BM, the image-forming layers BS1, BS2, BS3 being offset relative to each other at a specific angle and therefore arranged stacked on top of each other.

[0092] FIG. 4 shows a schematic diagram of two image forming layers BS1 and BS2, each having a different image motif involved in partial overlap and superposition, and the resulting corresponding effective local path difference LOGr resulting from the superposition.

[0093] Figure 5 shows a schematic diagram of an example of use, where the brightness contrast between a background H and a random object O located in a decorative element DE can be changed, and the brightness of the background H located in the center of the light field LF emanating from the lighting device BV is variable by a polarizing filter PF in the lighting device BV.

[0094] Figure 6 shows a schematic diagram of a manufacturing method for generating an image-forming layer BS (of a decorative element DE) by means of a liquid crystal material LC, in particular for applying a mesogenic layer MS, which generates the respective image motif BM according to a correspondingly (locally) addressable local optical path difference LOG.

[0095] The reactive mesogens RM in a corresponding spatial distribution according to local coordinates x, y are applied to the correspondingly oriented alignment layer OS according to an image-formed structuring (image motif BM) by an apparatus with a corresponding coating tool BW.

[0096] FIG. 7 shows a schematic diagram of an example of use, in which a specific optically anisotropic film layer FOi (film material) is used to design a specific and therefore resulting image information BIr. , in the form of a stacked arrangement, with corresponding partial overlap, where two film layers FO1, FO2 are shown in an exemplary manner having different image motifs BM1, BM2, which image motifs BM1, BM2, respectively, contrast with their surroundings, so that the local areas NBM1, NBM2 surrounding each of the image motifs BM1, BM2 must correspondingly stand out or can simply be cut out from the respective films.

Claims

1. A method for producing a decorative element (DE), comprising the steps of: Providing a transparent optical carrier material (TM) having a flat or curved surface and consisting of a glass or plastic substrate; applying a polarizing layer (PS) acting as an analyzer to one side of said carrier material (TM); applying a transparent optically functional layer (FS) as an image-forming layer (BS) made of an optically anisotropic material (OAM) having a layer thickness to the other side of the carrier material (TM); and image-forming spatially structuring said functional layer (FS) by a target-position-dependent dependence on the material properties of said optically anisotropic material (OAM) to generate said image-forming layer (BS) in the form of an image motif (BM), As a result, a configurable color contrast having a polarization interference color (PIF) determined according to said image motif (BM) is visible on the illuminated surface of said decorative element (DE) by illuminating it with polarized light, A method for producing a decorative element, in which a number of transparent optically functional layers (FSi) are applied as image-forming layers (BSi) with different image motifs (BMi), superimposed on one another in a defined manner, forming a composite material (V) and bonded to a resulting interacting optically functional layer (FSr), generating a resulting effective local optical path difference (LOGr) for said composite material (V).

2. 2. Method for producing a decorative element according to claim 1, characterized in that a transmissive polarizing layer (PSt) is used as a polarizing layer (PS) for producing an illuminating decorative element (DE) or a reflective polarizing layer (PSr) is used as a polarizing layer (PS) for producing a reflective decorative element (DE).

3. 3. Method for producing a decorative element according to claim 1 or 2, characterized in that the target position-dependent dependence of the material properties of the optically anisotropic material (OAM) is brought about by one or more local changes of: a) a change in the optical anisotropy, b) a change in the layer thickness, c) a change in the local configuration.

4. 4. Method for producing a decorative element according to any one of claims 1 to 3, characterized in that a local optical path difference (LOG), which can be set in a defined manner, is realized by a dependency of the material properties of the optically anisotropic material (OAM) on the target position, each value of the local optical path difference (LOG) corresponding to one defined polarization interference color (PIF) determining the image motif (BM).

5. 5. A method for producing a decorative element according to claim 4, characterized in that the local optical path difference (LOG) is realised to have a specific, settable constant value over the entire surface or over a defined portion of the surface of the decorative element (DE).

6. 6. A method for producing a decorative element according to claim 5, characterized in that the local optical path difference (LOG) is realised in a uniform manner for the defined portion of the surface of the decorative element (DE) and the settable constant value is close to zero, whereby each of the polarization interference colours (PIF) is generated achromatically for the uniform surface of the decorative element (DE).

7. 2. A method for producing a decorative element according to claim 1, characterized in that to form the functional layer (FS) an orientation layer (OS) is first applied to the carrier material (TM) and a liquid crystal based LC material (LC) is applied on top as optically anisotropic material (OAM).

8. Method for producing a decorative element according to claim 7, characterized in that the LC material (LC) is applied by a coating method followed by curing or by a printing technique.

9. 2. A method for producing a decorative element according to claim 1, characterized in that a film material (FO) is applied as optically anisotropic material (OAM) to form the functional layer (FS).

10. Method for producing a decorative element according to claim 9, characterized in that the film material (FO) is applied by lamination.

11. 11. A method for producing a decorative element according to claim 9 or 10, characterized in that a targeted spatial structure birefringence is induced in the film material (FO) by suitable processing means or a pre-existing intrinsic optical anisotropy in the film material (FO) is exploited to generate an image motif (BM).

12. 2. A method for producing a decorative element according to claim 1, characterized in that, if the optically anisotropic material (OAM) is realised as a film material (FO), several film layers (FOi) are applied as a stack to the carrier material (TM).

13. 13. Method for producing a decorative element according to claim 12, characterized in that the individual film layers (FOi) extend over specific defined local areas and each have different defined recesses and / or cutouts, which can be set based on each motif.

14. Use of a decorative element manufactured by a method for manufacturing a decorative element according to any one of claims 1 to 13, characterized in that the photo-optical effect is generated and influenced exclusively via the optical path in interaction with an external lighting device (BV) emitting unpolarized or polarized light with a variable polarization direction, the following operating modes being realized: a) Neutral Mode (NM): the decorative element (DE) has no polarization interference color (PIF) when illuminated by unpolarized light, and therefore the latent color graphic motif (FM) in the image-forming layer (BS) generated in the form of the image motif (BM) remains in principle invisible b) Presence mode (PM): the decorative element (DE) is illuminated with polarized light and the color graphic motif (FM) latent in the image-forming layer (BS) is visually displayed as the image motif (BM) according to the defined polarization interference color (PIF). c) Color Variation Mode (FVM): defined, infinitely variable color variations are possible in said Color Variation Mode (FVM) by means of the defined Polarized Interference Colors (PIF) in the color graphic motif (FM), said color variations in the decorative elements (DE) being brought about by a change in the polarization direction of polarized light.

15. 15. Use of a decorative element according to claim 14, characterized in that the selection and implementation of the operating modes (Neutral Mode (NM), Presence Mode (PM) and Color Variation Mode (FVM)) in the lighting device (BV) is performed by adjustment means (M) realized by a polarizing filter (PF) and its respective position in the optical path of the lighting.

16. The selection and implementation of a particular operation mode by the adjustment means (M) is performed a) for the neutral mode (NM) by removing the polarizing filter (PF) from the optical path, b) for the presence mode (PM) by introducing the polarizing filter (PF) into the optical path, and c) for the color variation mode (FVM) by appropriately rotating the polarizing filter (PF), and the disappearance in the neutral mode (NM) and the visibility in the presence mode (PM) are achieved.

16. Use of a decorative element according to claim 15, characterized in that it is possible to arbitrarily switch between said color variations in said color variation mode (FVM) and

17. Use of a decorative element produced by the method for producing a decorative element according to any one of claims 1 to 13 as an architectural element for producing light-optical effects in the exterior area of ​​a building or as a design element for interior design or object design.

18. 18. Use of a decorative element according to claim 17, characterized in its embodiment as a sign-carrying element.

19. Use of a decorative element according to claim 17, characterised in that the machining or cutting of said decorative element (DE) made of purely passive material is realised by means of a tool.

20. 7. Use of a decorative element manufactured by the method for manufacturing a decorative element according to claim 6, characterized in that the decorative element (DE) comprises a reflective polarizing layer (PSr) and the local optical path difference (LOG) has a constant value that can be set close to zero, the decorative element (DE) being arranged as a background surface (H) on which an object (O) to be displayed is presented, the object (O) and the background surface (H) being jointly illuminated by a lighting device (BV), so that, when the luminous intensity in the light field (LF) containing both the object (O) and the background surface (H) is unchanged, the luminance of the jointly illuminated object (O) remains unchanged by changing the polarization direction of the lighting device (BV), while only the luminance of the background surface (H) is infinitely dimmable.

Images