Multilayer Body and Method for Producing a Security Element
First Claim
1. A multilayer body, in particular security element for security documents, with an upper side and an underside, wherein the multilayer body has a metal layer, wherein in a first surface of the metal layer facing the upper side of the multilayer body or forming the upper side of the multilayer body and/or in a second surface of the metal layer facing the underside of the multilayer body or forming the underside of the multilayer body an optically active surface relief is molded at least in areas, wherein in at least one first area of the multilayer body the surface relief is formed by a first relief structure which, in at least one direction determined by an allocated azimuth angle, has a sequence of elevations and depressions, the elevations of which follow on from each other with a period P which is smaller than a wavelength of visible light, wherein the minima of the depressions lie on a base surface and the first relief structure has a relief depth t which is determined by the spacing of the maxima of the elevations of the first relief structure from the base surface in a direction perpendicular to the base surface, and wherein the profile shape and/or the relief depth t of the first relief structure is chosen such that the colored appearance of the light incident on the first area at least at one first angle of incidence and reflected directly by the metal layer in the first area or transmitted directly through the metal layer is modified, by plasmon resonance of the metal layer with the incident light.
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Accused Products
Abstract
A multilayer body (1, 2, 3) and a method for producing a security element are described. The multilayer body has a metal layer (21). An optically active surface relief is molded at least in areas in a first surface of the metal layer (21) facing the upper side of the multilayer body or forming the upper side of the multilayer body and/or in a second surface of the metal layer (21) facing the underside of the multilayer body or forming the underside of the multilayer body. In at least one first area (31 to 39) of the multilayer body the surface relief is formed by a first relief structure (61). In at least one direction (617) determined by an allocated azimuth angle, the first relief structure (61) has a sequence of elevations (612) and depressions (614), the elevations (612) of which follow on from each other with a period P which is smaller than a wavelength of visible light, wherein the minima of the depressions (614) lie on a base surface and the first relief structure (61) has a relief depth t which is determined by the spacing of the maxima of the elevations (612) of the first relief structure (61) from the base surface in a direction perpendicular to the base surface. The profile shape and/or the relief depth t of the first relief structure (61) is chosen such that the colored appearance of the light (52, 53) incident on the first area (31 to 39) at least at a first angle of incidence and directly reflected by the metal layer (21) in the first area or directly transmitted through the metal layer is modified, in particular is modified by plasmon resonance of the metal layer with the incident light.
23 Citations
46 Claims
- 1. A multilayer body, in particular security element for security documents, with an upper side and an underside, wherein the multilayer body has a metal layer, wherein in a first surface of the metal layer facing the upper side of the multilayer body or forming the upper side of the multilayer body and/or in a second surface of the metal layer facing the underside of the multilayer body or forming the underside of the multilayer body an optically active surface relief is molded at least in areas, wherein in at least one first area of the multilayer body the surface relief is formed by a first relief structure which, in at least one direction determined by an allocated azimuth angle, has a sequence of elevations and depressions, the elevations of which follow on from each other with a period P which is smaller than a wavelength of visible light, wherein the minima of the depressions lie on a base surface and the first relief structure has a relief depth t which is determined by the spacing of the maxima of the elevations of the first relief structure from the base surface in a direction perpendicular to the base surface, and wherein the profile shape and/or the relief depth t of the first relief structure is chosen such that the colored appearance of the light incident on the first area at least at one first angle of incidence and reflected directly by the metal layer in the first area or transmitted directly through the metal layer is modified, by plasmon resonance of the metal layer with the incident light.
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43. A method for producing a security element comprising:
manufacturing a multilayer body comprising a metal layer with an optically active surface relief molded into a first surface and/or a second surface opposite the first surface, wherein in at least one first area of the multilayer body the surface relief is formed by a first relief structure which, in at least one direction determined by an allocated azimuth angle, has a sequence of elevations and depressions, the elevations of which follow on from each other with a period P which is smaller than a wavelength of visible light, wherein the minima of the depressions define a base surface and the first relief structure has a relief depth t which is determined by the spacing of the maxima of the elevations of the relief structure from the base surface in a direction perpendicular to the base surface, and wherein the profile shape and/or the relief depth t of the first relief structure is chosen such that the colored appearance of the light incident on the first area at least at one first angle of incidence and reflected directly by the metal layer in the first area or transmitted directly through the metal layer is modified by plasmon resonance of the metal layer with the incident light. - View Dependent Claims (44, 45, 46)
Specification