Optically variable representation element
An optically variable representation element with a reflective surface region generates a respective three-dimensional representation for at least two different observation directions. The reflective surface region contains a respective multiplicity of reflective facets in a first and a second partial region, which at least partially overlap one another. The reflective facets are oriented such that the facets in the first partial region generate a first three-dimensional representation from the first observation direction and the facets in the second partial region generate a second three-dimensional representation from the second observation direction. The facets of the reflective surface region are provided at least regionally with sub-wavelength structures which generate the different colors of the three-dimensional representations in the overlap region.
1 . An optically variable representation element having at least one reflective surface region, which generates a three-dimensional representation upon observation in reflected light for each of at least two different observation directions,
wherein the three-dimensional representations at least partially overlap and have different colors at least in some regions in an overlap region, wherein
the at least one reflective surface region, in a first and a second subregion, which at least partially overlap one another, contains in each case a plurality of reflective facets that are formed by a micromirror arrangement having directed reflective micromirrors, which are oriented so that
the facets of the first subregion create a first three-dimensional representation having a first surface protruding and/or set back in relation to an actual spatial shape of the first surface for an observer from a first observation direction, and
the facets of the second subregion create a second three-dimensional representation having a second surface protruding and/or set back in relation to an actual spatial shape of the second surface for the observer from a second observation direction, and
the facets of the reflective surface region in the overlap region of the first and second subregion are provided at least in some regions with subwavelength structures, wherein the subwavelength structures create the different colors of the first and second three-dimensional representations,
wherein the subwavelength structures are formed by periodic structures and a period length of the subwavelength structures and linear dimensions of the micromirrors are matched to one another so that at least 10 complete periods of the subwavelength structures have space on each micromirror.
2 . The representation element according to claim 1 , wherein the facets of the reflective surface region are provided with a reflection-enhancing coating.
3 . The representation element according to claim 2 , wherein the facets of the reflective surface region are provided with a reflection-enhancing coating with a metallization, a refractive layer, and/or a thin film structure.
4 . The representation element according to claim 1 , wherein the facets of the reflective surface region are formed in an embossing lacquer layer.
5 . The representation element according to claim 4 , wherein the embossing lacquer layer is a thermoplastic or radiation-curing embossing lacquer layer.
6 . The representation element according to claim 1 , wherein the subwavelength structures are formed by periodic structures having a period length between 100 nm and 500 nm, and/or a depth between 50 nm and 400 nm.
7 . The representation element according to claim 1 , wherein the subwavelength structures are formed by one-dimensional grids or by two-dimensional grids.
8 . The representation element according to claim 7 , wherein the subwavelength structures have rectangular, square, hexagonal, or parallelogram-shaped grid symmetry.
9 . The representation element according to claim 1 , wherein at least two subwavelength structures are provided for creating the different colors, wherein the at least two subwavelength structures differ in period length and/or their-depth and/or profile shape.
10 . The representation element according to claim 1 , wherein the subwavelength structures for the different colors of the first and second three-dimensional representations are arranged in register with the facets of the reflective surface region, so that each facet is only covered by a respective specific type of subwavelength structures wherein the respective specific type of wavelength structures is characteristic for a respective color.
11 . The representation element according to claim 1 , wherein each color visible to an observer upon observation of the representation element is created by a respective specific type of subwavelength structures, wherein the respective specific type of subwavelength structures is characteristic for a respective color.
12 . The representation element according to claim 1 , wherein each color visible to an observer upon observation of the representation element contains mixed colors, which arise due to color mixing of colors of pixel-shaped partial regions having a dimension below a resolution limit of a human eye, and in which the colors of the pixel-shaped partial regions are each created by a respective specific type of subwavelength structures, wherein the respective specific type of subwavelength structure is characteristic for a respective color.
13 . The representation element according to claim 1 , wherein, in the overlap region, both the facets of the first subregion and the facets of the second subregion are provided at least in some regions with subwavelength structures, which create the different colors of the first and second three-dimensional representations.
14 . The representation element according to claim 1 , wherein the three-dimensional representations have different shapes and/or sizes.
15 . The representation element according to claim 1 , wherein the representation element is a security element for securing value objects.
16 . The representation element according to claim 1 , wherein the facets of the reflective surface region are formed by micromirrors having a linear dimension between 3 μm and 100 μm.
17 . An optically variable representation element having at least one reflective surface region, which generates a three-dimensional representation upon observation in reflected light for each of at least two different observation directions,
wherein the three-dimensional representations at least partially overlap and have different colors at least in some regions in an overlap region, wherein
the at least one reflective surface region, in a first and a second subregion, which at least partially overlap one another, contains in each case a plurality of reflective facets, which are oriented so that
the facets of the first subregion create a first three-dimensional representation having a first surface protruding and/or set back in relation to an actual spatial shape of the first surface for an observer from a first observation direction, and
the facets of the second subregion create a second three-dimensional representation having a second surface protruding and/or set back in relation to an actual spatial shape of the second surface for the observer from a second observation direction, and
the facets of the reflective surface region in the overlap region of the first and second subregion are provided at least in some regions with subwavelength structures, wherein the subwavelength structures create the different colors of the first and second three-dimensional representations,
wherein the first and second three-dimensional representations have a same shape and size and are arranged congruently, so that the three-dimensional representations only differ from the at least two different observation directions due to the color differing at least in some regions.
18 . An optically variable representation element having at least one reflective surface region which generates a three-dimensional representation upon observation in reflected light for each of at least two different observation directions,
wherein the three-dimensional representations at least partially overlap and have different colors at least in some regions in an overlap region, wherein
the at least one reflective surface region, in a first and a second subregion, which at least partially overlap one another, contains in each case a plurality of reflective facets, which are oriented so that
the facets of the first subregion create a first three-dimensional representation having a first surface protruding and/or set back in relation to an actual spatial shape of the first surface for an observer from a first observation direction, and
the facets of the second subregion create a second three-dimensional representation having a second surface protruding and/or set back in relation to an actual spatial shape of the second surface for the observer from a second observation direction, and
the facets of the reflective surface region in the overlap region of the first and second subregion are provided at least in some regions with subwavelength structures, wherein the subwavelength structures create the different colors of the first and second three-dimensional representations,
wherein the first and second subregion are interleaved with one another,
wherein the subregions are formed by a plurality of strips arranged alternately adjacent to one another or by partial regions interleaved with one another in two dimensions.