Patent ID: 8928978
Filing Date: 2015-01-06
Classification: B42D,G02B

Abstract:
1. A film element having a replication layer, wherein an optically active surface structure is shaped in a first surface of the replication layer, and wherein the surface structure is formed in at least a first region of the film element by a first diffractive surface relief comprising a plurality of successive reflection elements following a first envelope curve, wherein the reflection elements respectively comprise a reflective element surface arranged substantially parallel to a base plane and at least one flank adjoining the adjacent element surface or surfaces, the element surfaces of adjacent elements are spaced in a direction perpendicular to the base plane such that the element surfaces of at least three adjacent elements each have a different height with respect to each other and the base plane, with a first optical spacing or a plurality of the first optical spacing, wherein the first optical spacing is between 150 nm and 800 nm, the first envelope curve has a spatial frequency of between 100 L/mm and 2000 L/mm and an optical depth at at least one location of more than 450 nm and the relief shape and the spatial frequency of the envelope curve are so selected that the incident light is diffracted into one or more first directions to represent a first item of information, the color value of said diffracted light being further influenced by interference determined by the first optical spacing, wherein the optical depth is defined by the geometric difference between a minimum and a maximum perpendicular distance of the envelope curve with respect to the base plane, and wherein, in at least one second region, the surface structure is formed by a second surface relief which differs from the first surface relief and which represents a second item of information, and wherein the second surface relief also comprises a plurality of successive elements following a second envelope curve, wherein the elements respectively comprise an element surface arranged substantially parallel to the base plane and at least one flank adjoining the adjacent element surface or surfaces, the element surfaces of adjacent elements are spaced in a direction perpendicular to the base plane, with a second optical spacing or a plurality of the second optical spacing, wherein the second optical spacing is between 150 nm and 800 nm, the second envelope curve has a spatial frequency of between 100 L/mm and 2000 L/mm and an optical depth of more than 450 nm and the relief shape and spatial frequency of the second envelope curve are so selected that the incident light is diffracted in one or more second directions to represent the second item of information, the color value of which is further determined by the second spacing, wherein the optical depth is defined by the geometric difference between a minimum and a maximum perpendicular distance of the second envelope curve with respect to the base plane, and wherein an area of the surface structure is subdivided into a plurality of mutually adjoining domains which in at least one direction are of a dimension of less than 300 μm and provided in the domains of a first group of domains are respectively at least one of the first region and at least one the second region.