Optically variable areal pattern
The present invention relates to an optically variable surface pattern having a substrate that comprises a first and a second surface region, the two surface regions being developed in such a way that the first surface region presents, in a first viewing angle range (α 1 ) a bulged-appearing first depiction, and the second surface region presents, in a second viewing angle range (α 2 ) that is different from the first viewing angle range (α 1 ), a bulged-appearing second depiction.
1. An optically variable areal pattern comprising:
a substrate that comprises a first and a second areal region, the two areal regions being developed in such a way that the first areal region presents, in a first viewing angle range, a bulged-appearing first depiction, and the second areal region presents, in a second viewing angle range that is different from the first viewing angle range, a bulged-appearing second depiction,
wherein the first and the second areal regions are nested within each other,
wherein over at least a part of the first viewing angle range only the bulged-appearing first depiction is perceptible and over at least a part of the second viewing angle range only the bulged-appearing second depiction is perceptible, and
wherein at least one of the two areal regions present the bulged-appearing depiction by imitating the reflective behavior of a bulged surface, in which the imitation of the reflection behavior of the bulged surface is effected by optically effective relief patterns, in which each of the relief patterns reconstruct, for each depiction, local changes in slope of the respective depiction to be presented, in which the local changes in slope reproduced by the relief patterns are executed such that incident parallel light is reflected in the corresponding viewing angle range.
2. The optically variable areal pattern according to claim 1 , in which the two areal regions are developed as reflective areal regions.
3. The optically variable areal pattern according to claim 1 , in which the optically effective relief patterns are developed in a lacquer layer.
4. The optically variable areal pattern according to claim 1 , in which the optically effective relief patterns are provided with a reflective or at least reflection-increasing coating.
5. The optically variable areal pattern according to claim 1 , in which the optically effective relief patterns comprise micromirrors.
6. The optically variable areal pattern according to claim 5 , in which the micromirrors comprise dimensions between 2 μm and 300 μm.
7. The optically variable areal pattern according to claim 1 , in which the optically effective relief patterns comprise diffraction-optically effective diffraction patterns.
8. The optically variable areal pattern according to claim 1 , in which the two viewing angle ranges do not overlap.
9. The optically variable areal pattern according to claim 1 , in which the first and/or second areal region reflect/reflects incident parallel light in an angle range of at least 10°.
10. A security element having an optically variable areal pattern according to claim 1 .
11. A value document having an optically variable areal pattern according to claim 1 .
12. A method for producing an optically variable areal pattern comprising:
a substrate that comprises a first and a second areal region, the two areal regions being developed in such a way that the first areal region presents, in a first viewing angle range, a bulged-appearing first depiction, and the second areal region presents, in a second viewing angle range that is different from the first viewing angle range, a bulged-appearing second depiction, the first and the second areal regions being nested within each other, such that over at least a part of the first viewing angle range only the bulged-appearing first depiction is perceptible and over at least a part of the second viewing angle range only the bulged-appearing second depiction is perceptible, and
wherein at least one of the two areal regions present the bulged-appearing depiction by imitating the reflective behavior of a bulged surface, in which the imitation of the reflection behavior of the bulged surface is effected by optically effective relief patterns, in which each of the relief patterns reconstruct, for each depiction, local changes in slope of the respective depiction to be presented, in which the local changes in slope reproduced by the relief patterns are executed such that incident parallel light is reflected in the corresponding viewing angle range, wherein:
the slope profiles of the depictions to be presented are determined,
the slope profile of the first depiction and the slope profile of the second depiction are modified via different transformations, and
the substrate having the two areal regions is manufactured based on the modified slope profiles.