Optically variable surface pattern, value document having optically variable surface pattern and method for producing an optically variable surface pattern

Abstract

The invention relates to an optically variable surface pattern. The surface pattern comprises a first sub-wavelength structure which defines a first surface region and is designed to create at least a first colour impression for the viewer from at least one first viewing perspective. The surface pattern also comprises a translucent, coloured layer which defines a second surface region and is designed to create a second colour impression. The first surface region overlaps at least partly with the second surface region and forms a first overlap region so that the first sub-wavelength structure in the first overlap region is covered by the translucent, coloured layer. The first overlap region is designed to create at least a third colour impression for the viewer from the at least one first viewing perspective. The first sub-wavelength structure has a distance from the translucent, coloured layer in the first overlap region. The invention also relates to a value document having such an optically variable surface pattern and to a method for producing an optically variable surface pattern.

Description

Optically variable surface pattern, value document with optically variable surface pattern and method for producing an optically variable surface pattern

[0001] The invention relates to an optically variable surface pattern with a sub-wavelength structure and a translucent colored layer, a value document with an optically variable surface pattern and a method for producing an optically variable surface pattern.

[0002] Optically variable surface patterns are known in the prior art and are used as security features and / or security elements that realize motion effects, for example, using microreflectors. In particular, security elements are known in the prior art in which colors are generated using nanostructures with structural sizes in the sub-wavelength range. Sub-wavelength structures, in particular sub-wavelength gratings, are described, for example, in DE 10 2007 061 979 A1.

[0003] Such nanostructures can, for example, be combined with microstructures by superimposing them. A combination of micromirrors with nanostructures on them can create colorful rolling and / or 3D effects. The "rolling bar" effect using microreflectors is shown, for example, in DE 10 2010 047 250 A1, and a 3D effect is shown in DE 10 2009 056 934 A1. The micromirrors essentially generate the rolling and / or 3D effect, and the nanostructures color them or can also create multi-colored effects. For example, the viewer is given the impression of a moving, colorful motif. The publications WO 2015 / 078572 A1 and W TO 2016 / 180522 A1 also shows such exemplary motion effects. The microreflectors or microlenses are arranged relative to a main plane in such a way that the motif exhibits or depicts the motion effect when the security element is tilted and / or rotated.

[0004] Typically, as described, for example, in document WO 2021 / 028076 A1, such micro- or nanostructures are molded into a transparent embossing lacquer and coated with a metallic or high-refractive-index layer.

[0005] Often, variable area patterns, such as those described above, can only produce pale, low-contrast, and / or pastel-colored images. Furthermore, some colors in the spectrum can sometimes be poorly reproduced or not reproduced at all.

[0006] It is an object of the present invention to provide an optically variable surface pattern with alternative properties and effects.

[0007] It is a further object of the present invention to provide an optically variable surface pattern with alternative color impressions, in particular with regard to the hue, the color saturation and / or the brightness.

[0008] It is a further object of the present invention to provide an optically variable surface pattern with high security against counterfeiting.

[0009] A further task is to ensure that the recognizable effect of the optically variable surface pattern appears particularly striking and / or aesthetic to the viewer.

[0010] It is a further object of the present invention to provide an optically variable surface pattern which is not perceived as a disturbing element and makes an object to be secured thereby appear more aesthetically pleasing.

[0011] Furthermore, it is an object to provide a corresponding method for producing an optically variable surface pattern and a value document provided with the optically variable surface pattern.

[0012] At least one of these problems is solved by the respective subject matter of the independent claims.

[0013] According to one aspect, an optically variable surface pattern comprises: a first sub-wavelength structure which defines a first surface area and is designed to generate at least one first color impression for the viewer from at least one first viewing perspective; and a translucent colored color layer which defines a second surface area and is designed to generate a second color impression, wherein the first surface area at least partially overlaps with the second surface area and forms a first overlap area, such that the first sub-wavelength structure is covered by the translucent colored color layer in the first overlap area and the first overlap area is designed to generate at least one third color impression for the viewer from the at least one first viewing perspective, wherein the first sub-wavelength structure in the first overlap area has a distance from the translucent colored color layer.

[0014] The distance is the distance between the first sub-wavelength structure and the translucent color layer. Distance, therefore, means that the first sub-wavelength structure is spaced apart from the translucent color layer in the first overlap area.

[0015] The distance can preferably be the shortest distance in a relief of the sub-wavelength structure to the translucent color layer.

[0016] Therefore, an optically variable surface pattern with alternative properties and effects can be provided. Furthermore, an optically variable surface pattern with alternative color impressions, particularly with regard to hue, color saturation, and / or brightness, can be provided. Furthermore, an optically variable surface pattern with a high degree of counterfeit security can be provided. Furthermore, the perceptible effect of the optically variable surface pattern is particularly striking to the observer and / or appears aesthetically pleasing. An optically variable surface pattern can also be provided that is not perceived as a disruptive element and lends a secured object a more aesthetic appearance.

[0017] The optically variable surface pattern comprises a combination of one or more color-generating or color-impression-producing, in particular color-effect-generating or color-effect-producing sub-wavelength structures with at least one additional translucent colored layer. The first sub-wavelength structure generates at least a first color impression and is therefore a color-impression-producing and in particular a color-effect-generating or color-effect-producing sub-wavelength structure. A color impression can be generated solely by emitting, reflecting, and / or scattering a color that is independent of the viewing perspective. A color effect can comprise a color impression generated by emitting, reflecting, and / or scattering a color that is dependent on the viewing perspective.The first color impression can be generated by an optical color effect, for example, through interference or plasmonic effects on a nanostructure, such as a nanograting. A color impression and / or a color effect can generally be objectively perceivable, but as a color effect, it depends on the viewing perspective. Multiple color impressions can also be generated by sub-wavelength structures; for example, a point in an image of the first sub-wavelength structure can exhibit different colors and / or shimmer in different colors.

[0018] The translucent color layer creates a second color impression, which can be created, for example, by color particles, a dye and / or nanoparticles.

[0019] The sub-wavelength structures can comprise plasmonic periodic sub-wavelength structures, preferably with metallic elements, such as a thin metal layer on the sub-wavelength structure. The superposition or overlapping of the two layers has the effect that the translucent color layer shifts the color of one of the color-generating sub-wavelength structures toward a higher and / or more intense chroma and / or a different color tone or color angle. At least in a first surface area there is at least one sub-wavelength structure which produces at least one first color or a first color impression, in particular a first color effect, in reflection and / or transmission. In another surface area there may be no sub-wavelength structure or at least one different sub-wavelength structure, so that this surface area can appear in a different color. At least the first surface area is covered and / or coated at least in part with the translucent color layer, so that in the area of ​​the covering and / or coating a changed, in particular a more colorful and / or at least a different mixed color can arise.

[0020] An optically variable surface pattern can be part of a security element and / or security feature for a value document or represent such a security feature. A security feature can therefore comprise the optically variable surface pattern. The optically variable surface pattern can, for example, be arranged on a display field of the security element. The first and / or second surface area and / or the overlap area can be arranged on the display field.

[0021] The first viewing perspective can correspond to a reflection perspective or a transmission perspective with respect to a light source and the display field or the first, second, and / or overlapping areas. In the reflection perspective, light from a light source is reflected and / or scattered at the respective area before reaching the viewer's eye. In the transmission perspective, the light from the light source passes through the respective area before reaching the viewer's eye.

[0022] The viewing perspective can encompass discrete angles or entire angular ranges, with the angular ranges lying within a range corresponding to the viewing of the respective surface area either from the top side of the respective area, i.e., in reflection perspective, or from the bottom side of the respective area, i.e., in transmission perspective. The top side of the respective area of ​​the optically variable surface pattern is visible from above (reflection perspective), and the bottom side is visible from through (transmission perspective).The viewing perspective can be defined by the angle between the viewing axis (eye of the observer - targeted point on the optically variable surface pattern) and the perpendicular (z-axis) on a main plane (xy-axis) of the optically variable surface pattern as well as the angle between the viewing axis (eye of the observer --- targeted point on the optically variable surface pattern) and the predetermined top-bottom axis and / or right-left axis.

[0023] The first sub-wavelength structure can be formed in the first overlap area by the translucent color layer with respect to the first viewing perspective in plan view (in reflection), i.e. the sub-wavelength structure lies beneath the translucent color layer in a layer system - and is applied accordingly before the translucent color layer on a substrate during the layering of the layer system. In this case, “covered” therefore means in particular that the sub-wavelength structure lies beneath the translucent color layer with respect to a surface normal of the substrate and / or a main surface of the variable surface pattern. In an arrangement that is intended to be suitable for a viewing perspective in transparency, the layering order can also be the other way around, with the translucent color layer lying beneath the sub-wavelength structure so that the sub-wavelength structure covers the translucent color layer in an overlapping area.

[0024] The third color impression can result from a coloring and / or mixed color effect of the first color impression and the second color impression. Therefore, the third color impression can result from the color combination of the first and the second color impression. A color impression can comprise at least one of the following properties: hue, color saturation and brightness. The first color impression can be generated exclusively by the first sub-wavelength structure, whereas the second color impression can be generated exclusively by the translucent color layer. The first color impression is therefore created either by the first sub-wavelength structure before coating with the translucent color layer or in an area that is not covered by the translucent color layer or any other color-providing or color-generating layer.color-generating layer and / or structure overlaps or superimposes, i.e., for example, outside the overlap area, provided that an area of ​​the first sub-wavelength structure is present there. The second color impression can also arise, for example, where the translucent color layer does not overlap with the first sub-wavelength structure or any other color-providing or color-generating or color-generating layer and / or structure, i.e., where essentially only the translucent color layer is present.

[0025] Along with hue and brightness, color saturation is one of the three characteristics or properties of a color perceived by humans. It describes the quality of the color nuance, for example, whether it corresponds more to a chromatic or achromatic color. The opposite of high color saturation can be described as a grayish tint or dullness. Color saturation can correspond to at least one of the following characteristics: brilliance, degree of chroma, chromaticity, degree of chroma, chromaticity, colorfulness, color intensity, color strength, color depth, intensity, purity, purity, saturation, and can be related to the proportion of white in the primary hue.

[0026] The hue (primary hue) essentially corresponds to the wavelength of reflected, scattered, transmitted, and / or emitted light. A change in hue can therefore correspond to a shift in the wavelength of the primary hue.

[0027] Achromatic colors are white, black, and their mixtures in various shades of gray. Their color saturation is zero; they leave no color impression and are without any color cast. Chromatic colors are colors with a chromatic effect, i.e., colors that are clearly different from black, white, and neutral gray. Pure colors are colors with maximum color saturation. The purest colors are the spectral colors.

[0028] The color impression can be objectively captured, particularly through camera capture, for example, in stereo. The color impression can depend, in particular, on the properties of the incident light. For example, if red light is irradiated, only red light can be scattered, reflected, and / or transmitted.

[0029] The first subwavelength structure in the first overlap area can have a distance from the translucent color layer that is not equal to 0. The distance can be between the highest point on the subwavelength structure with respect to a z-direction and the lower side of the translucent color layer. The z-direction corresponds to the direction of the surface normal of the principal planes of the display field (xy field). If two subwavelength structures are superimposed, the distance d corresponds to the shortest distance between the superimposed subwavelength structure and the translucent color layer.

[0030] For example, an embossing varnish, which may have the sub-wavelength structure, is arranged on the visible side of a metal layer. This means that the embossing varnish can be located between an ink layer and a sub-wavelength structure (e.g., a plasmonic periodic sub-wavelength structure), for example, in the sequence metal layer – embossing varnish – ink layer. Subsequent overprinting, for example, in banknote printing, can also be applied indirectly, i.e., not directly, to a sub-wavelength structure, particularly to a plasmonic sub-wavelength structure. This can be done by a protective varnish or, in the case of security threads, an adhesive layer separating the sub-wavelength structure from the translucent colored ink layer, thus defining a distance between them.The advantageous technical effect of such an arrangement can be that a distance d between the sub-wavelength structure and the translucent color layer of more than 1 pm, and in particular of more than 2 pm or more, allows for predictability of the resulting mixed color effect. As explained in more detail below, it is advantageous that the translucent color layer is not applied directly to the sub-wavelength structure and therefore rests against it.

[0031] In particular, a planar, homogeneous, uniformly thick, and translucent color layer can be applied over the subwavelength structure, resulting in a homogeneous and / or well-defined mixed color effect. Near-field effects often lead to significantly increased absorption of the dyes in the near field, making it difficult to predict or precisely match a desired mixed color. This can be overcome by maintaining a suitable distance d between these layers.

[0032] For example, if the sub-wavelength structure comprises nanostructures and is applied to and / or comprises microstructures (microreflectors and / or microlenses), a better color effect can be achieved if the color layer, i.e., the translucent color layer, is (well-defined) spaced from the microstructures. It is particularly advantageous to choose a relatively thin translucent color layer in terms of cost-effectiveness during production and the color effect.

[0033] Without a gap, i.e. if the translucent colored paint layer were applied directly, in the case of micromirrors with a height of around 3 pm, for example, an average layer of translucent colored paint with a thickness of around 2 pm would cover the mirrors at the upper end of a relief with a thickness of only around 0.5 pm and at the lower end with a thickness of around 3.5 pm. Thus, a reflected light beam at the lower end of the microreflector would appear very dark, whereas a light beam reflected at the upper end of the microreflector would appear less colorful. A flat color layer with a thickness of around 2 pm at a higher level, i.e. with a gap between the sub-wavelength structure and the translucent colored paint layer, can prevent this. The gap can be reliably created by a leveling layer. The distance can therefore be more than 0.5 um, advantageously at least 1 um, and more preferably at least 2 pm.The distance is defined—as already described—by the smallest distance between the relief structure and the translucent color layer (for example, from the highest point of the sub-wavelength structure to the translucent color layer). This distance is particularly suitable for achieving desired, predetermined and / or well-defined mixed color effects.

[0034] The first area can overlap with the second area as follows:

[0035] First: Partial overlap of both surface areas, so that the first surface area does not overlap with the second surface area in one part of the area but overlaps with the second surface area in another part of the area and thus forms the overlap area.

[0036] Second: The second surface area completely overlaps with the first surface area, so that either a) both surface areas are identical in their areal extent; or b) the first surface area is larger or smaller than the second surface area, i.e. one of the surface areas is completely encompassed by the other surface area.

[0037] A leveling layer can be arranged between the translucent color layer and the first sub-wavelength structure to achieve a predetermined and / or suitable distance between the sub-wavelength structure and the translucent color layer. The translucent color layer can also optionally have a thickness of approximately 1-3 μm, in particular approximately 2 μm, which is preferably as homogeneous as possible across the surface, i.e., exhibits hardly any deviations in thickness over a large area.

[0038] As already described, the sub-wavelength structure is typically located in a relief structure with unevenness in the nanometer and / or micrometer range. In the case where a flat and homogeneous translucent color layer is to be applied to the sub-wavelength structure, it is advantageous to provide a leveling layer, in particular a colorless and essentially visible-light transparent leveling layer, to compensate for the unevenness of the sub-wavelength structure so that it can then be subsequently coated with the translucent color layer. Applying the leveling layer allows for the provision of a homogeneous and / or flat layer over the sub-wavelength structure onto which the translucent color layer can be applied.Within the specified range of layer thickness of the translucent color layer, the mixed color effect can be particularly aesthetic and / or suitable for achieving or producing the previously described technical effects and advantages. Furthermore, an optically variable surface pattern with alternative and well-defined and / or precisely predictable and / or predetermined color impressions, particularly with regard to hue, color saturation, and / or brightness, can be provided.

[0039] The third color impression may differ from the first color impression and / or the second color impression in at least one of the following properties: hue, color saturation and brightness.

[0040] The translucent color layer can change the hue, color saturation, and / or brightness of the first color impression of the sub-wavelength structure. Sub-wavelength structures often produce a pale color impression in the pastel color range. Therefore, the translucent color layer can, for example, cause the first color impression of the sub-wavelength structures to be perceived as a richer, stronger, more intense, brighter, and / or stronger color impression, the third color impression. The second color impression, which is created solely by the translucent color layer, can also be influenced by the color effect of the sub- Wavelength structure in the overlap area can be influenced in the same way. Therefore, an optically variable surface pattern with a variety of alternative color impressions, particularly with regard to hue, color saturation, and / or brightness, can be provided. Furthermore, an optically variable surface pattern with a high level of counterfeit security can be provided. Furthermore, the perceptible effect of the optically variable surface pattern is particularly striking to the observer and / or appears aesthetically pleasing. An optically variable surface pattern can also be provided that is not perceived as a disruptive element and lends a secured object a more aesthetic appearance.

[0041] The optically variable surface pattern may further comprise an embossed layer, wherein the first sub-wavelength structure may comprise an embossed structure in the embossed layer and preferably a reflective metal layer may be arranged on the embossed structure.

[0042] One or more sub-wavelength structures can be easily incorporated into and / or applied to an optically variable surface pattern by applying an embossing layer, in particular an embossing lacquer layer, to a substrate in which a predetermined relief structure corresponding to the embossing structure can be present and / or incorporated. The relief or the relief structure can have a planar extent in a main plane and / or surface parallel to the substrate, which is defined as an xy plane or xy surface. The relief can have heights and depths in a z direction that runs perpendicular to the xy plane or xy surface or is perpendicular to it. An embossing lacquer layer is particularly advantageous because it can be applied to a substrate as a substantially liquid medium, and a relief structure or an embossed structure can be incorporated during or after the embossing lacquer layer has dried.The relief structure, which can form a sub-wavelength structure, is particularly stable and resistant to external influences, since the embossing lacquer layer is a solid, resistant material.

[0043] A metallic structure in the form of a metal layer and / or a grating can be applied to the relief structure in order to generate reflection effects, plasmonic effects, near-field effects, scattering and / or interference effects.

[0044] The first sub-wavelength structure, in particular the embossed structure, may have a nanostructure and / or a microstructure, and the microstructure may optionally have a plurality of microreflectors or micromirrors and / or microlenses and / or be applied to a plurality of microreflectors and / or microlenses.

[0045] Microreflectors, micromirrors and / or microlenses are elements that can create particularly aesthetic and / or memorable moving, 3D and / or floating effects in images. For this purpose, it can be determined in advance, for example, digitally, how the Nano- and / or microstructures are intended to interact with the incident light to create the aforementioned optical effects and impressions for the viewer. The nanostructures can be suitable for creating color effects.

[0046] The color impression-generating, in particular the color effect-generating sub-wavelength structure can be applied to microstructures, in particular to micromirrors, so that they can be superimposed on one another and the resulting colors can be combined, for example, with running or 3D effects and registered exactly as such.

[0047] The first sub-wavelength structure can be designed to superimpose a scrolling effect and / or a 3D effect. In other words, the first sub-wavelength structure can superimpose a scrolling effect, a color effect, a floating effect, and / or a 3D effect, particularly if the first sub-wavelength structure has the microreflectors and / or microlenses (or if its relief structure also includes this microstructure). Color, scrolling, 3D, and / or floating effects of representations presented or generated in this way can appear particularly memorable and aesthetically pleasing and, moreover, can be difficult to counterfeit.

[0048] The optically variable surface pattern may further comprise a second sub-wavelength structure. The second sub-wavelength structure may be superimposed and / or overlapped with the first sub-wavelength structure and / or it may be present in a region that does not overlap or overlap with the first sub-wavelength structure.

[0049] The second sub-wavelength structure can therefore define a third surface area. Thus, there can be a third surface area of ​​the second sub-wavelength structure that does not overlap with the first surface area of ​​the first sub-wavelength structure. Alternatively, there can be a third surface area of ​​the second sub-wavelength structure that only partially or completely overlaps with the first surface area of ​​the first sub-wavelength structure.

[0050] The second sub-wavelength structure can also be designed to superimpose a moving effect and / or a 3D effect and / or to generate a fourth color impression for the viewer under the at least one first viewing perspective and / or under a different viewing perspective. The second sub-wavelength structure (or its relief structure) can comprise microstructures (microlenses and / or microreflectors) and / or nanostructures. The second sub-wavelength structure can, for example, comprise the previously described microstructure for generating a moving and / or 3D effect, which is at least partially superimposed with the first sub-wavelength structure having a color effect.

[0051] The third surface area can therefore at least partially overlap with the first surface area and / or the second surface area and form a second overlap area, The second overlap region can optionally be designed to produce at least a fifth color impression for the viewer from the at least one first viewing perspective, which differs in hue, color saturation, and / or brightness from the first, second, third, and / or fourth color impression. Additionally or alternatively, the third surface area can have scrolling, 3D, and / or floating effects, which, when overlapped with the first and / or second surface area and / or the first overlap area, result in effect combinations.

[0052] Such optically variable surface patterns with a combination of color, flow, 3D and / or floating effects can also appear particularly memorable and aesthetic and, moreover, can be difficult to counterfeit.

[0053] According to one aspect, a value document has the optically variable surface pattern according to an embodiment.

[0054] Therefore, a value document provided with the optically variable surface pattern can be provided, which has all the already mentioned advantages and technical effects of the optically variable surface pattern and its embodiments.

[0055] According to one aspect, a method for producing an optically variable surface pattern comprises the steps of: providing a carrier film or a substrate; applying a first sub-wavelength structure in a first surface area on the carrier film, and applying a translucent color layer in a second surface area on the carrier film that overlaps the first surface area, such that the translucent color layer covers the first sub-wavelength structure in a first overlap area, wherein a distance exists between the first sub-wavelength structure and the translucent color layer.

[0056] Therefore, a method for producing the optically variable surface pattern can be provided which has all the advantages and technical effects already mentioned.

[0057] The carrier film can be a removable and / or peelable element from the optically variable surface pattern, which can be removed from the optically variable surface pattern before or after application to a security feature. However, the carrier film can also be part of a security feature.

[0058] The order of application and / or layering of a sandwich structure produced by the method can be as follows in a first overlap area: Carrier film - sub-wavelength structure (in particular embossed layer with embossed structure) - optional metal layer and / or possibly a leveling layer - a translucent colored paint layer. Alternatively, the sandwich structure produced by the process can look like this: carrier film - translucent colored paint layer - sub-wavelength structure. Layers, (protective) lacquers, and / or films can also be present between and / or above and / or below the aforementioned layers or elements of the sandwich structures.

[0059] The application of the first sub-wavelength structure of the optically variable surface pattern can comprise: applying a first embossed layer, in particular an embossed lacquer layer; and optionally embossing an embossed structure into the first embossed layer, wherein the embossed structure can represent or comprise the first sub-wavelength structure. The embossed structure can also represent or comprise a second sub-wavelength structure. For example, the embossed structure can correspond to an at least partial superposition of the first and the second sub-wavelength structure. The first and / or the second sub-wavelength structure can, for example, have a plurality of microstructures, such as microreflectors, and the other sub-wavelength structure can, for example, have a nanostructure.

[0060] The method may further comprise: applying a leveling layer, in particular between the first sub-wavelength structure and the translucent color layer.

[0061] The method may further comprise: embossing a second sub-wavelength structure comprising a second embossed structure into the first embossed layer in a third surface area; and / or applying a second embossed layer and embossing a second sub-wavelength structure into the second embossed layer in a third surface area.

[0062] The method may further comprise applying a reflective metal layer to the glazing and / or the first sub-wavelength structure. The metal layer may also possibly be understood as part of the first sub-wavelength structure.

[0063] An optically variable surface pattern can be understood as a pattern and / or a representation of an object which is variable depending on the viewing perspective, for example with regard to the colour effect or the colour impact or the colour impression and / or with regard to the representation of the pattern and / or the object, which can have a colouring, 3D and / or a running effect, for example, depending on the viewing perspective.

[0064] Sub-wavelength structures can be or include structures that are so small that no first-order or higher-order diffraction effects occur under normal light incidence. The structure sizes of sub-wavelength structures are usually smaller than the Wavelength of light in the visible range. Different structures can be used for different effects: (1) Sub-wavelength gratings (also called "zeroth-order gratings" in the literature) (2) Regular ID (one-dimensional) or 2D (two-dimensional) gratings with periods in the sub-wavelength range ≤ about 400 nm produce colors in the specular reflection (“zero-order”) (3) Gratings with metallic coating: Here, plasma effects occur which are used to produce colours (4) Grating with dielectric (especially high refractive index) coating.

[0065] Typical structure sizes of sub-wavelength structures usually include structures with dimensions of ≤ approximately 400 nm. Subwavelength structures can comprise subwavelength gratings. The grating periods of the subwavelength gratings are therefore preferably between 10 nm and 500 nm, more preferably between 50 nm and 400 nm, and most preferably between 100 nm and 350 nm.

[0066] A first sub-wavelength structure defines a first surface area, and therefore the first surface area is characterized by the fact that the first sub-wavelength structure essentially fills it. A translucent colored layer defines a second surface area, and therefore the second surface area is characterized by the fact that the translucent colored layer essentially fills it.

[0067] An optically variable surface pattern can comprise: a first surface area which has first sub-wavelength structures which produce a first colour when viewed in reflection and / or transmission; a second surface area in which no sub-wavelength structure or a different sub-wavelength structure is present, so that this surface area has no colour or a different colour than the first surface area; and a translucent (coloured) colour layer which at least partially covers or covers the first surface area, characterized in that a viewer sees a mixed colour from the colour of the first sub-wavelength structures and the translucent (coloured) colour layer in the areas in which the translucent (coloured) colour layer covers the first surface area when viewed above and / or through.

[0068] In other words, an optically variable surface pattern may comprise: a first sub-wavelength structure in a first surface area; and a translucent colored layer, which at least partially overlaps with the first surface area in a first overlap area, so that for a viewer when viewing the optically variable Surface pattern from a viewing side in a first viewing area (or area that is viewed) which corresponds to the first overlap area, a mixed color effect of the first sub-wavelength structure with the translucent color layer is created, characterized in that for the viewer when viewing the optically variable surface pattern from the viewing side in at least a second viewing area (or area that is viewed) a different color or mixed color effect is created by the first sub-wavelength structure or the translucent color layer. In this area, the color effect of the first sub-wavelength structure or the color effect of the translucent color layer or the mixed color effect of the translucent color layer with the second sub-wavelength structure is therefore present.

[0069] The mixed color may have a different color impression than that of the sub-wavelength structure and / or the translucent color layer; preferably, the mixed color may have a higher chroma and / or a different color tone than the color (or color impression) that would be produced by the first sub-wavelength structures without the translucent color layer.

[0070] The sub-wavelength structures in the first surface area can be overlaid with a microstructure, in particular with micromirrors. Additionally or alternatively, the second surface area can contain microstructures, in particular micromirrors, that are not overlaid with sub-wavelength structures or with layers of a different color.

[0071] According to one aspect, a value document comprises one of the optically variable surface patterns described herein. All advantages mentioned for the aforementioned optically variable surface patterns also apply to the corresponding value document, which becomes particularly forgery-proof due to the corresponding security feature. The same also applies to the method for producing the optically variable surface pattern.

[0072] Fig. 1 is a schematic representation of an optically variable surface pattern according to an embodiment with a sub-wavelength structure and a translucent color layer,

[0073] Fig. 2 a)-f) is a schematic representation of first, second and possibly third surface areas and the respective overlap areas according to various embodiments;

[0074] Fig. 3 is a schematic representation of an optically variable surface pattern according to another embodiment with a sub-wavelength structure and a translucent color layer;

[0075] Fig. 4 is a schematic representation of an optically variable surface pattern according to another embodiment with a sub-wavelength structure and a translucent color layer;

[0076] Fig. 5 is a schematic representation of an optically variable surface pattern according to another embodiment with sub-wavelength structures and a translucent color layer;

[0077] Fig. 6 is a schematic representation of a first sub-wavelength structure overlaid with a second sub-wavelength structure, according to one embodiment;

[0078] Fig. 7 is a schematic representation of an optically variable surface pattern according to another embodiment with sub-wavelength structures and a translucent colored layer;

[0079] Fig. 8 is a schematic representation of an optically variable surface pattern according to another embodiment with a sub-wavelength structure and a translucent color layer;

[0080] Fig. 9 is a schematic side view of the layer structure of an optically variable surface pattern according to an embodiment; and

[0081] Fig. 10 a) and b) are schematic side views of layer structures of optically variable surface patterns according to two embodiments.

[0082] Unless otherwise stated, the same reference numerals are used below for identical and equivalent elements. A redundant description of recurring features and, where appropriate, a redundant use of recurring reference numerals is partially avoided. The various embodiments and features of the figures described below are expressly combinable and should not be understood as complete versions. Effect of a changed color impression: color saturation

[0083] The optically variable surface pattern 1 according to the invention can achieve an increase in color saturation. The color saturation of pale sub-wavelength structures 2 (here magenta) can be increased, for example, by coating such sub-wavelength structures with a translucent colored layer 3 (here also magenta).

[0084] Fig. 1 is a schematic representation of an optically variable surface pattern 1 according to an embodiment with a sub-wavelength structure 2 (first sub-wavelength structure 2) in a first surface region 4 and a translucent colored layer 3 in a second surface region 5. The sub-wavelength structure 2 can, for example, comprise nanostructures.

[0085] A left representation ID, a middle representation mD, and a right representation rD are shown, with the left representation ID showing only a sub-wavelength structure 2, the middle representation mD showing only a translucent color layer 3, and the right representation rD showing a combination of the two, i.e., the finished, entire optically variable surface pattern 1. In the following embodiments, analogous representations are shown on the left, middle, and right (left and middle combined).

[0086] The composite optically variable surface pattern 1 (representation on the right-hand side or right-hand representation rD) in Fig. 1 comprises the overlay of the left representation ID and the central representation mD. The motif shown on the left shows an exemplary number “25” and comprises the first sub-wavelength structure 2, which defines a first surface area 4 in the form of the number and which, without further elements, creates a first color impression for the viewer when viewed from a first viewing perspective, namely a pale magenta tone Fh. The motif shown in the middle shows a colored surface and comprises the translucent colored color layer 3, which defines a second square surface area 5 and which creates a second color impression for the viewer when viewed from the first viewing perspective, also a pale magenta tone FD.The black contour Fh of the number "25" can be part of the first sub-wavelength structure 2 or an additional element that comprises a further sub-wavelength structure or merely corresponds to a color layer. The first surface area 4 in the shape of the "25" can thus be provided with a border, which can be covered, in particular, by a third surface area 8 with a further, second color-imparting sub-wavelength structure or a colorless structure, for example with dark or even black-looking "moth-eye structures."

[0087] On the right-hand side of Fig. 1, the superimposition of both motifs to form the optically variable surface pattern 1 is shown. The second surface area 5 completely overlaps the first surface area 4, with the second surface area 5 being larger than the first surface area 4. The resulting overlap area 6 is distinguished by the fact that, from the viewing perspective, at least a third color impression is created for the viewer, namely a "rich" or strong magenta tone Fh. The third color impression is stronger than the first and second color impressions because the first and second color impressions are combined and / or added to form the third color impression. The non-overlapping area of ​​the second surface area 5 continues to have the unchanged pale magenta tone.

[0088] As shown in Fig. 1, images that actually appear pale can be represented according to the invention with "rich" colors, i.e. with a stronger or greater color saturation. The color of the translucent color ink layer 3 can, as shown here, be printed essentially over the entire surface and, in the finished optically variable surface pattern 1, form and / or make a foreground and / or background appear with the same or similar color tone but lower color saturation and higher brightness. One possible application could be microimages from a Moire magnifier, where the motifs are typically very small. For example, the number "25" shown in Fig. 1 could have surface dimensions (length and / or width) of only a few micrometers or several tens of micrometers, as is common with Moire magnifiers on security features in the banknote sector but is hardly achievable in normal color printing using conventional printing processes.In such microlens features, the color could be present as a coloring of the microlenses instead of as a separate color layer (colored embossed layer, in particular embossed lacquer).

[0089] In Fig. I, the translucent color layer 3 is applied over the entire surface so that it completely covers the first and surface areas 4 and defines the second surface area 5, which is larger than the first surface area 4.

[0090] In the following, using Fig. 2a)-f), various possible embodiments are shown by way of example and in general terms, i.e. regardless of the effect achieved, how different surface areas can overlap in order to achieve a mixed colour effect, possibly with a superimposed running, 3D and / or floating effect.

[0091] Fig. 2a) shows the partial overlap of the first surface area 4, which is defined by the areal extension of a first sub-wavelength structure (not shown here), with the second surface area 5, which is defined by the areal extension of a translucent colored ink layer (not shown here), thus forming the overlap area 6, which comprises part of the first surface area 4 and part of the second surface area 5. The translucent colored ink layer lies above the first sub-wavelength structure in the overlap area 6 with respect to the z-direction emerging from the plane of representation. A type of sandwich structure is thus formed from at least two layered elements, wherein the translucent colored ink layer covers the first sub-wavelength structure in the overlap area 6 in the xy plane with respect to the z-axis perpendicular thereto.

[0092] In the first surface area 4, excluding the overlap area 6, a first color impression is created by the first sub-wavelength structure. In the second surface area 5, excluding the overlap area 6, a second color impression is created by the translucent color layer. The first and / or the second color impression can each be a very weak color impression, for example corresponding to the impression of very pale colors. The translucent color layer can also be so thin that the second color impression on its own is only weakly perceived. In the overlap area 6, the third color impression is created by the overlap of the first surface area 4 of the first sub-wavelength structure with the second surface area 5 of the translucent color layer. The first sub-wavelength structure can moreover be at least partially overlaid with a second structure, for example a microstructure, in order to achieve an optically variable motif effect, in particular moving, 3D and / or floating effects. However, the first sub-wavelength structure can also have other moving, 3D and / or floating effects in addition to a color effect.

[0093] Fig. 2b) shows the partial overlap of the first surface area 4 by the entire second surface area 5, thus forming the overlap area 6, which comprises a part of the first surface area 4 and the entire second surface area 5. The translucent color layer thus only partially covers the first sub-wavelength structure, with the translucent color layer having no area outside the overlap area 6. The first surface area 4 thus completely encompasses the second surface area 5, and the second surface area 5 therefore corresponds to the overlap area 6.

[0094] Fig. 2c) shows the complete overlap of the first surface area 4 by the second surface area 5, thus forming the overlap area 6, which encompasses the entire first surface area 4 and part of the second surface area 5. The translucent color layer thus covers the first sub-wavelength structure and protrudes beyond it, with the first sub-wavelength structure having no area outside the overlap area 6. The second surface area 5 thus completely encompasses the first surface area 4, and the first surface area 4 therefore corresponds to the overlap area 6.

[0095] In Fig. 2d) - f), a third surface area 8 is additionally shown, which is defined by a second color-imparting sub-wavelength structure, a colorless structure, or a microstructure (not shown here). The second sub-wavelength structure and / or the microstructure can exhibit a coloring, rolling, 3D, and / or floating effect.

[0096] In Fig. 2d), the third surface area 8 partially overlaps only the first surface area 4, partially overlaps only the second surface area 5, and partially overlaps both surface areas 4, 5. In the second overlap area 9, namely the overlap area 9 of all surface areas 4, 5, 8, the translucent color layer can cover the first and second sub-wavelength structures. The first sub-wavelength structure can overlap with the second sub-wavelength structure, i.e., in particular, can be embossed together in an embossing lacquer layer. In the overlap area 9 of all surface areas 4, 5, 8, For example, a fifth color impression can be created, in particular when all surface areas 4, 5, 8 alone achieve an individual color impression and in the overlap area 9 a color combination effect resulting from the combination of these color impressions is achieved.

[0097] Fig. 2e) corresponds to the situation in Fig. 2b) with regard to the first and second surface areas 4, 5. The third surface area 8 is completely enclosed by the first and second surface areas 4, 5, with the third surface area 8 being smaller than the second surface area 5 and the second surface area 5 being smaller than the first surface area 4. The second overlap area 9 corresponds to the third surface area 8.

[0098] Fig. 2f) corresponds to the situation in Fig. 2c) with regard to the first and second surface areas 4, 5. The third surface area 8 is completely enclosed by the first and second surface areas 4, 5, with the third surface area 8 being smaller than the first surface area 4 and the first surface area 4 being smaller than the second surface area 5. The second overlap area 9 corresponds to the third surface area 8.

[0099] Further possible embodiments of the overlap with the third surface area 8 are not shown here. However, it is also possible in principle for the third surface area 8 to correspond to the first surface area 4 and / or the second surface area 5 and / or the first free area area 6. Additionally or alternatively, it is also possible for the third surface area 8 not to overlap with the first surface area 4 and / or the second surface area 5 and / or the first overlap area 6.

[0100] Fig. 3 is a schematic representation of an optically variable surface pattern 1 according to another embodiment with a sub-wavelength structure 2 and a translucent color layer 3. In this embodiment of Fig. 3, the translucent color layer 3 itself also has a two-dimensional motif. Furthermore, the second surface area 5, which is defined by the translucent color layer 3, can only partially overlap the first surface area 4.

[0101] The left-hand illustration of Fig. 3 again shows the first sub-wavelength structure 2, which defines the first surface area 4, namely in the form of the number "25" (color impression F3a). The middle illustration of Fig. 3 again shows a translucent color layer 3, which defines a second surface area 5, which forms a two-dimensional motif, namely a square with star-shaped recesses and a star emerging from the square, which is located within the Square has a recess (color impression F3Q. In both images, i.e. the left and the middle image, the respective surface areas are not overlapped with each other and the first sub-wavelength structure 2 in the left image can produce the first color impression in isolation and the translucent color layer 3 in the middle image can produce the create a second color impression in isolation. In the right-hand illustration, the left and middle illustrations overlap each other, specifically in such a way that the translucent color layer 3 lies over and covers the first sub-wavelength structure 2, so that in the right-hand illustration, in the overlap area 6, a fourth color impression (color impression F34) is created, which is achieved by the combination.

[0102] This results in four areas with different color impressions: the first color impression (color impression F3s) is created by the first sub-wavelength structure 2 in the area of ​​the recesses of the translucent color layer in the shape of three stars on the number "2" of the "25"; the second color impression (color impression F3r) is created by the translucent color layer 3 in the area that does not overlap with the first sub-wavelength structure 2; the third color impression (color impression F3e) is created in the overlap area 6 by the combination of the first and the second color impression; and the color impression (color impression F31 / 5) of the base or substrate remains in the area in which there is again a sub-wavelength structure 2 or a translucent color layer (e.g. colorless if the embossed structure is provided with an aluminum metallization). Effect of a changed color impression: Generation of mixed colors

[0103] Fig. 4 is a schematic representation of an optically variable surface pattern 1 according to a further embodiment with a sub-wavelength structure 2 and a translucent colored layer 3.

[0104] In addition to increasing color saturation, as shown in Figs. 1 and 3, a translucent color layer 3 can also change the hue of a sub-wavelength structure 2 by overlapping it. For example, it has been proven that a color impression comprising a rich green is difficult to produce with certain sub-wavelength structures 2. A golden color impression, on the other hand, is easy to achieve using sub-wavelength structures 2. For example, if a sub-wavelength structure 2 producing a golden color impression is overlapped with a cyan-colored translucent color layer 3, a third color impression comprising a rich green can be created.

[0105] The left-hand illustration of Fig. 4 shows - similar to the previously mentioned example of the first color impression of a golden color (color impression F4s) - a sub-wavelength structure 2, which creates the first color impression of a golden color (color impression F4j) in the first surface area in the form of the number "25". The middle illustration shows a translucent color layer 3, which has the second color impression (color impression F44) of a cyan-blue color in the second surface area 5. As shown in the right-hand illustration of Fig. 4, the overlap area 6, which corresponds to the number “25”, in the third color impression of a green lifting color (color impression F4s), since this color impression is created by the color mixture.

[0106] Fig. 5 is a schematic representation of an optically variable surface pattern 1 according to a further embodiment with two color effect-generating sub-wavelength structures 2, 2' and a translucent colored color layer 3. More precisely, the optically variable surface pattern 1 of Fig. 5 has two different sub-wavelength structures 2, 2', each of which generates different color impressions (possibly color effects). This can be seen in the left-hand illustration: The first color impression-generating sub-wavelength structure 2 achieves a first color impression (golden color, color impression F5s) in the first surface region 4 in the shape of the number "25". The second color effect-generating sub-wavelength structure 2' has a fourth color impression (magenta tone, color impression F5i) in the third surface region 8 in the shape of a square surrounding the number.

[0107] The middle illustration shows the translucent color layer 3 in the second surface area 5, which is square, with a second color impression (cyan-blue, color impression F54).

[0108] After overlapping the two images (on the left side and in the middle), a third color impression (color impression F5s) is created in a first overlap area 6 (first sub-wavelength structure 2 in golden color + translucent color layer in cyan-blue), which appears greenish, and in a second overlap area 6' (second color effect-generating sub-wavelength structure 2' in magenta + translucent color layer in cyan-blue), a color impression is created that appears blue. Additional optical effects: combination with micromirrors

[0109] Fig. 6 is a schematic representation of a first sub-wavelength structure 2 overlaid with a first microstructure, here micromirrors 7, according to an embodiment.

[0110] In addition to the color impression, additional optical variable effects, such as color, running, 3D and / or floating effects, can be generated by superimposing sub-wavelength structures with other structures, as shown in Fig. 6. For example, nanostructures can be combined with larger microstructures, in particular micromirrors. If, for example, the first sub-wavelength structure 2 is applied in the form of nanostructures to the micromirrors 7, as shown in Fig. 6, then, for example, running effects and / or 3D effects, which are generated by means of the micromirrors 7, can be combined with the color impression and optionally the color effects of the first sub-wavelength structure 2. The relief structure, which which contains the micromirrors 7 as a microstructure and the sub-wavelength structure 2, can be produced in one embossing step with the advantage of an exact arrangement to one another.

[0111] Fig. 7 is a schematic representation of an optically variable surface pattern 1 according to a further embodiment with several sub-wavelength structures 2, 2' of a microstructure 7 and a translucent colored layer 3. Two possible tilt axes are indicated in this figure, namely the top-bottom axis o - u and the right-left axis r - 1.

[0112] As already described for Fig. 6, the embodiment of Fig. 7 has a first color effect generating sub-wavelength structure 2, a second color effect generating sub-wavelength structure 2' and two microstructures 7 superimposed thereon. In the left illustration of Fig. 7, similar to Fig. 5, two color impression generating sub- Wavelength structures 2, 2', which do not overlap, are shown. The first color impression-generating sub-wavelength structure 2 defines the first surface area 4 in the form of the number "25" in gold. The remaining area surrounding the number in the form of a square is defined by the second color impression-generating sub-wavelength structure 2\, which appears magenta. In addition, the color impression-generating sub- Wavelength structures 2, 2' are superimposed on microstructures 7, in particular micromirrors. In the first surface area 4, the microstructure 7 makes the number "25" appear as a protruding object (3D effect or bulge effect). Preferably only outside the first surface area (optionally also within), the (second) optically variable microstructure 7 creates the impression of a "running bar" (running effect). The position of the bar, indicated in the figure as an unshaded area, changes depending on the viewing direction, thus also when the surface pattern is tilted and / or rotated.

[0113] In other words, micromirrors 7 are arranged to create a scrolling effect. For example (as shown), when the security element is tilted from left to right (i.e., along the right-left axis r-1 and about an axis perpendicular to the right-left axis r-1), a scrolling bright bar is generated. The bar can also move from left to right or from right to left. The micromirrors that create the scrolling effect are overlaid with the subwavelength structure 2' (outside the number "25" of the first area 4) (the subwavelength structure 2' that creates a magenta tone). In another area 4, the subwavelength structure 2, which depicts the value number or number "25" in gold, is overlaid with the micromirrors that make the number appear three-dimensionally curved.

[0114] In the middle illustration of Fig. 7, as in some previous embodiments, the translucent color layer 3 is shown in the second (square-shaped) surface area 5 with a cyan-blue color impression (color impression F7Q). In the right illustration, the The left representation of the sub-wavelength structures 2, 2', 7 overlaps with the middle representation of the translucent color layer 3. Thus, all color impressions and color effects created by the sub-wavelength structures 2, 2', 7 are combined with the color impression of the translucent color layer 3.

[0115] If one overprints such an arrangement (left image) with a cyan-blue translucent color layer, the result is the impression of a greenish number “25” emerging from the plane (color impression F7s) against a bluish background (color impression F7ö), which has a lighter bluish “rolling bar”.

[0116] Fig. 8 is a schematic representation of an optically variable surface pattern 1 according to a further embodiment with a sub-wavelength structure 2, a gap region 15 without a color impression-generating sub-wavelength structure and a translucent color layer 3.

[0117] Fig. 8 shows a simpler embodiment compared to Fig. 7, wherein the number "25" either represents a gap region 15 (gap 14 without a color-effect-generating layer, color impression F8s) in which no structures are present at all, or is formed as a curved-appearing number by micromirrors without a sub-wavelength structure. In this case, the corresponding region then appears in the color of the translucent color layer 3 and can be significantly brighter than regions in which the impression of a mixed color exists, which is a combination of the color impression of the sub-wavelength gratings and the color impression of the translucent color layer, so that in this embodiment, multi-colored representations with high light-dark contrasts can be achieved.

[0118] The left-hand illustration of Fig. 8 shows a cyan-blue sub-wavelength structure 2 in the background (color impression F8i) combined with a foreground area without a sub-wavelength structure (e.g., only micromirrors with a convex effect) and coated with a bright yellow translucent color layer 3 (color impression F84) (middle illustration). This creates a bright yellow number "25" (color impression F84) against a rich, deep green background (color impression F85) after overlapping the left and middle illustrations. The yellow or gold number is created by the metallization.

[0119] Fig. 9 is a schematic side view of the exemplary layer structure of an optically variable surface pattern 1 according to an embodiment. A security element according to an embodiment can be realized as a foil-based layer system in which an embossed (lacquer) layer 11 is applied to a carrier foil 13 or a substrate. In the left-hand surface area, no relief structure is embossed into the embossed layer 11, but rather only a reflective (metal) layer 12, an optional leveling layer 10 and the overlying translucent color layer 3 are applied. In the middle surface area, additional In addition to the elements already mentioned for the left surface area, an embossed structure 11a having a sub-wavelength structure 2 is embossed into the embossed layer 11. In the right surface area, in addition to the elements already mentioned for the left surface area, another embossed structure 11b having a different sub-wavelength structure 2' is embossed into the embossed layer 11.

[0120] The reflective coating 12 may preferably comprise a metallization, such as aluminum, silver and / or copper, and / or a high-refractive coating comprising, for example, ZnS, Ti O2.

[0121] The layer structure shown is merely an example. If the illustrated embodiments of the optically variable surface pattern 1 are to be viewed in translucency, i.e., in transmission and / or from the other side (e.g., from below), the colored ink could be provided beneath the reflective layer or metallization. The colored ink layer 3 could, for example, be arranged between the carrier film 13 and the embossed layer 11 or on the underside of the carrier layer 13. With a suitable film structure, the carrier film 13 can be removed after the security element according to the invention has been transferred to an object to be secured (e.g., a banknote).

[0122] Figs. 10a) and b) are schematic side views of layer structures of optically variable surface patterns according to two embodiments. Fig. 10a) shows a translucent colored ink layer 3 coated with an embossed layer 11. An embossed structure 11a, 11b, which can represent a sub-wavelength structure 2, is embossed into the embossed layer 11. The shortest distance between the embossed structures and the planar translucent colored ink layer 3 is indicated by the reference symbol d. A reflective layer, in particular a metal layer, can be applied to the embossed structure 11a, 11b. During the production of this embodiment, the translucent colored ink layer 3 may initially have been applied to a substrate (not shown here) and then the embossed layer 11. The embossed structure 11a, 11b may then have been embossed into the embossed layer 11. The sub-wavelength structure 2 can be understood as the embossed structure 11a, 11b with or without the reflective metal layer.

[0123] Fig. 10b) shows an embossed layer 11 into which an embossed structure 11a, 11b, possibly comprising a sub-wavelength structure 2, is embossed. A leveling layer 10 is arranged directly or indirectly on the embossed layer 11, for example, over a reflective metal layer, which serves to create a flat surface over the relief structure of the embossed structure 11a, 11b. The leveling layer 10 can in particular comprise a transparent material, such as a clear varnish. On the surface created by the leveling layer 10 The translucent colored ink layer 3 is applied to the planar surface. During production, the embossed layer 11 can be applied first to a substrate (not shown here), and then the additional layers can be applied one above the other. The shortest distance between the embossed structures and the planar translucent colored ink layer 3 is indicated by the reference symbol d.

[0124] In general, the embodiments described herein are shown for viewing in transmission. The invention is primarily directed at security elements or security features whose representations are viewed in plan view or in reflection. However, it is also possible for all embodiments to utilize the inventive principle of color mixing of colors, translucent color layers, and subwavelength structures in transmission.

[0125] In the following, the color fields of the described figures, 1, 3-5, 7 and 8, which are shown as black and white contour drawings, are assigned the corresponding color impressions or colors or shades that they have by way of example in the embodiments:

[0126] Fig. 1 : Fl i — colorless; Fh - black (black contour); Fh - pale magenta tone; FD - pale magenta tone; Fh - strong magenta tone

[0127] Fig. 3: F3i - colorless; F3? - black (black contour); F3} - pale magenta tone; F34 - pale magenta tone; F3? - colorless; F3e - strong magenta tone

[0128] Fig. 4: F4i - colorless; F4z - black (black contour); F4s - yellow or gold tone; F44 - cyan tone, F4s - rich green tone

[0129] Fig. 5: F5j - pale magenta tone; F5z - black (black contour); F5s - yellow or gold tone; F54 --- cyan tone; F5s --- rich green tone, F5e --- rich blue / violet tone

[0130] Fig. 7: F7i - pale magenta tone with a streaking effect (bright bar); F7i - black (black contour); F7< - yellow or gold tone with a 3D effect (bright bulge); F74 --- cyan-blue tone, F7s - rich green tone with a 3D effect (bright bulge); F7Ö -- rich blue-violet tone with a streaking effect (bright bar)

[0131] Fig. 8: F8i - cyan-blue tone; F82 - black (black contour); F83 - colorless; F84 - yellow or gold tone; F85 - rich green tone List of reference symbols I Optically variable surface pattern 2, 2' color effect-generating first or second sub-wavelength structure 3 translucent colored paint layers 4 First area 5 Second area 6, 6' First and second overlap area 7 Second sub-wavelength structure that generates a running and / or 3D effect 8 Third area 9 Further second overlap area 9a Overlap area with second surface area 10 Leveling layer II Embossing layer 11 a First embossed structure 1 1 b Second embossed structure 12 Reflective metal layer 13 Carrier film 14 Gap without color effect-generating layer 15 Gap area 100 value document d distance Flx-F8y color fields in Figures 1, 3-5, 7 and 8 1 left ID Left representation mD Middle representation o top r right rD Right representation u bottom

Claims

TI Patent claims 1. An optically variable surface pattern (1) comprising: a first sub-wavelength structure (2) defining a first surface area (4) and designed to produce at least one first color impression for the observer under at least one first viewing perspective;and a translucent colored paint layer (3) which defines a second surface area (5) and is designed to produce a second color impression, wherein the first surface area (4) at least partially overlaps with the second surface area (5) and forms a first overlap area (6), so that the first sub-wavelength structure (2) in the first overlap area (6) is covered by the translucent colored paint layer (3) and the first overlap area (6) is designed to produce at least one third color impression for the viewer from the at least one first viewing perspective, wherein the first sub-wavelength structure (2) in the first overlap area (6) has a distance (d) from the translucent colored paint layer (3); 2. Optically variable surface pattern (1) according to claim 1, wherein a leveling layer (10) is arranged between the translucent colored ink layer (3) and the first sub-wavelength structure (2), and the translucent colored ink layer (3) preferably has a thickness of approximately 1 pm to 3 pm, in particular approximately 2 pm.

3. Optically variable surface pattern (1) according to claim 1 or 2, wherein the third color impression differs from the first color impression and / or the second color impression in at least one of the following properties: hue, color saturation and brightness.

4. Optically variable surface pattern (1) according to one of the preceding claims, further comprising an embossed layer (11), wherein the first sub-wavelength structure (2) comprises an embossed structure (11a) in the embossed layer and preferably a reflective metal layer (12) is arranged on the embossed structure (11a).

5. Optically variable surface pattern (1) according to one of the preceding claims, wherein the first sub-wavelength structure (2), in particular the embossed structure (11a) has a nanostructure and / or a microstructure and the microstructure optionally has a plurality of microreflectors and / or microlenses and / or is applied to a plurality of microreflectors and / or microlenses.

6. Optically variable surface pattern (1) according to one of the preceding claims, wherein the distance (d) is at least 0.5 µm, preferably at least 1 µm and more preferably at least 2 µm.

7. Optically variable surface pattern (1) according to one of the preceding claims, further comprising a second sub-wavelength structure (7) which defines a third surface region (8) and is designed to produce a running effect and / or a 3D effect and / or to produce a fourth color impression under the at least one first viewing perspective for the observer.

8. Optically variable surface pattern (1) according to claim 7, wherein the third surface region (8) at least partially overlaps with the first surface region (4) and the second surface region (5) and forms a second overlap region (9), wherein the second overlap region (9) is optionally designed to generate at least one fifth color impression for the viewer under the at least one first viewing perspective, which differs in hue, color saturation and / or brightness from the first, second, third and / or fourth color impression.

9. A value document (100) having an optically variable surface pattern (1) according to one of claims 1 to 8.

10. A method for producing an optically variable surface pattern (1), comprising the steps: Providing a carrier film (13); .Applying a first sub-wavelength structure (2) in a first surface area (4) on the carrier film (13); and Applying a translucent colored paint layer (3) in a second surface area (5) overlapping the first surface area (4) on the carrier film (13), so that the translucent colored paint layer (3) covers the first sub-wavelength structure (2) in a first overlap area (6), wherein a distance (d) exists between the first sub-wavelength structure (2) and the translucent colored paint layer (3).

11. The method according to claim 10, wherein the application of the first sub-wavelength structure (2) comprises: Applying a first embossed layer (11), and Embossing an embossed structure (11 a) into the first embossed layer (1 1).

12. The method of claim 10 or 11, further comprising Applying a leveling layer (14) between the first sub-wavelength structure (2) and the translucent colored paint layer (3).

13. The method according to claim 12, further comprising: Embossing a second sub-wavelength structure (7) comprising a second Embossed structure (11b) in the first embossed layer (11) in a third surface area (4); or Applying a second embossing layer and embossing a second sub-wavelength structure into the second embossing layer in a third surface area (4).

14. The method according to any one of claims 10 to 13, further comprising: Applying a reflective metal layer (12) to the translucent color layer (3) and / or to the first sub-wavelength structure (2).

Images