Visually variable security element

• US 10,639,925 B2
• Filed: 05/04/2016
• Issued: 05/05/2020
• Est. Priority Date: 05/08/2015
• Status: Active Grant

• Current Assignee: Giesecke & Devrient (Giesecke & Devrient GmbH)
• Original Assignee: Giesecke & Devrient (Giesecke & Devrient GmbH)
• Inventors: Fuhse, Christian
• Primary Examiner(s): Grabowski, Kyle R
• Application Number:
  US15/572,531
• Publication Number:
  US 20180117947A1
• Time in Patent Office: 1,462 Days
• CPC Class Codes: B42D 25/23 Identity cards
• CPC Class Codes: B42D 25/24 Passports
• CPC Class Codes: B42D 25/29 Securities; Bank notes
• CPC Class Codes: B42D 25/324 Reliefs
• CPC Class Codes: B42D 25/328 Diffraction gratings; Holograms
• CPC Class Codes: B42D 25/351 Translucent or partly translucent parts, e.g. windows
• CPC Class Codes: B42D 25/355 Security threads
• CPC Class Codes: B42D 25/373 Metallic materials
• CPC Class Codes: B42D 25/378 Special inks
• CPC Class Codes: B42D 25/425 by deformation, e.g. embossing

Abstract

An optically variable security element having an areal motif region provided in a depiction region with a plurality of reflective, planar facets. Each planar facet is characterized by an inclination angle against the plane of the areal motif region, which inclination angle has, as inclination components, a parallel component parallel to a target curve in a center position, and a normal component perpendicular to the target curve in the center position. For the planar facets in the depiction region, a first of the two inclination components are chosen dependent on the distance of the respective facet from the target curve, and a second of the two inclination components being chosen in a predetermined spreading range independently of the distance of the respective facet from the target curve.

Claims

1. An optically variable security element for securing valuable articles that viewing-angle-dependently displays a motif having at least one curve depiction that, from a first viewing direction, is visible as a target curve in a center position within a depiction region and that, when the security element is tilted about two different predetermined axes, moves within the depiction region in different directions away from the center position, having

an areal motif region that is provided in the depiction region with a plurality of reflective, planar facets,

each planar facet being characterized by an inclination slope against the plane of the areal motif region, which inclination slope has, as inclination components, a parallel component parallel to the target curve in the center position, and a normal component perpendicular to the target curve in the center position,

wherein a direction of a vector defining each inclination component indicates the respective direction of rising facet level and an absolute value of the vector defining each inclination component indicates the slope in the respective direction, such that the inclination components together yield the total slope N of the planar facet;

and

for the planar facets in the depiction region, a first of the two inclination components being chosen dependent on the distance of the respective facet from the target curve, and a second of the two inclination components being chosen in a predetermined spreading angle range independently of the distance of the respective facet from the target curve,

wherein the second inclination component of the planar facets varies irregularly in the spreading angle range.

2. The security element according to claim 1, wherein the first inclination component of the planar facets increases or decreases monotonically, with the distance of the respective facet from the target curve.

3. The security element according to claim 2, wherein the first inclination component of the planar facets increases or decreases strictly monotonically with the distance of the respective facet from the target curve.

4. The security element according to claim 2, wherein the first inclination component of the planar facets increases or decreases linearly with the distance of the respective facet from the target curve.

5. The security element according to claim 1, wherein the second inclination component of the planar facets varies irregularly in the spreading angle range according to a random distribution or a pseudorandom distribution.

6. The security element according to claim 1, wherein the planar facets are cast in an embossing lacquer and are provided with a reflection-increasing coating.

7. The security element according to claim 1, wherein the first and second inclination component of the facets have a first or a second spreading angle range, respectively, and in that the size of the second spreading angle range is between 80% and 120% of the size of the first spreading angle range.

8. The security element according to claim 1, wherein the first inclination component is the normal component and the second inclination component is the parallel component of the facets, and in that, for a viewer, the curve depiction floats below or above the plane of the areal motif region.

9. The security element according to claim 1, wherein the first inclination component is the parallel component and the second inclination component is the normal component of the facets, and in that the curve depiction displays an orthoparallactic movement behavior when the security element is tilted.

10. The security element according to claim 1, wherein, as the target curve, the curve depiction displays a closed curve.

11. The security element according to claim 1, wherein, as the target curve, the curve depiction displays a curve having one or more curve ends, and in that the spreading angle range of the second inclination component of the facets is diminished in the region of each of the curve ends compared with its size in the curve interior.

12. The security element according to claim 11, wherein a surface of the planar facets in the region of each of the curve ends are blackened or demetallized.

13. The security element according to claim 11, wherein in the region of each of the curve ends randomly oriented mirrors or other, non-directionally reflective patterns are provided.

14. The security element according to claim 1, wherein, as the target curve, the curve depiction displays an alphanumeric character, a symbol or a geometric shape, selected from the group of a circle, an oval, a triangle, a rectangle, a hexagon, and a star shape.

15. The security element according to claim 1, wherein the motif includes at least a first and a second curve depiction that, from a first or second viewing direction, respectively, is visible as the first or second target curve, respectively, in a center position within a first or second depiction region, respectively, the two curve depictions moving in different directions when the security element is tilted.

16. The security element according to claim 15, wherein, in the areal motif region, the depiction regions of the first and the second curve depiction are arranged adjacent to each other or nested within one another.

17. The security element according to claim 15, wherein the two curve depictions move in different, opposing directions when the security element is tilted.

18. The security element according to claim 6, wherein the reflection-increasing coating or the reflective ink layer has a color-shift effect.

19. The security element according to claim 1, wherein the planar facets are embossed in a reflective ink layer.

20. The security element according to claim 1, wherein the security element is a security thread, a tear strip, a security band, a security strip, a patch or a label for application to a security paper or a value document.

21. A method for manufacturing an optically variable security element according to claim 1, in which

a desired target curve and a desired movement behavior of the target curve when the security element is tilted about two different axes are defined,

a depiction region for the target curve is determined in which, when the security element is tilted, the target curve moves away from a center position in accordance with the defined movement behavior,

in an areal motif region in the determined depiction region, a plurality of reflective, planar facets having an inclination slope against the plane of the areal motif region are arranged and aligned in such a way that they have, as inclination components, a parallel component parallel to the target curve in the center position, and a normal component perpendicular to the target curve in the center position,

wherein a direction of a vector defining each inclination component indicates the respective direction of rising facet level and an absolute value of the vector defining each inclination component indicates the slope in the respective direction, such that the inclination components together yield the total slope N of the planar facet;

for the planar facets in the depiction region, a first of the two inclination components being chosen dependent on the distance of the respective facet from the target curve, and a second of the two inclination components being chosen in a predetermined spreading angle range independently of the distance of the respective facet from the target curve,

wherein the second inclination component of the planar facets varies irregularly in the spreading angle range.