Optically variable security element having reflective surface region

Patent metadata

Field	Value
Publication number	US-11623465-B2
Application number	US-201917258666-A
Country	US
Kind code	B2
Filing date	Jul 9, 2019
Priority date	Jul 9, 2018
Publication date	Apr 11, 2023
Grant date	Apr 11, 2023

Abstract

An optically variable security element wherein the areal expansion whereof defines a z direction standing perpendicularly thereon, and has a multicolored, reflective areal region. The areal region includes two relief structures arranged at different height levels in the z direction. The relief structures are each supplied with an ink coating which produce a different color impression. The ink coating of the relief structure disposed at a higher level is configured in the feature region as a regular or irregular grid with grid elements and grid spaces. The dimensions of the grid elements and/or grid spaces are below 140 μm at least in one direction, so that, in the feature region, for a viewer from at least one viewing angle, the ink coating of the relief structure disposed at a lower level is visible through the grid spaces of the ink coating of the relief structure disposed at a higher level.

First claim

The invention claimed is:

1. An optically variable security element, the surface expansion of which defines a z direction standing perpendicularly thereon, with a multicolored, reflective areal region, wherein
the multicolored, reflective areal region includes two relief structures separated by a top-coat layer or a transparent embossing lacquer layer, the two relief structures arranged at different height levels in the z direction,
the relief structures are each supplied with an ink coating that produce a different color impression,
the two relief structures overlap in a feature region,
the ink coating of the relief structure disposed at a higher level is configured in the feature region as a regular or irregular grid with grid elements and grid spaces, and
the dimensions of the grid elements and/or grid spaces are below 140 μm at least in one direction, so that, in the feature region, for a viewer from at least one viewing angle, the ink coating of the relief structure disposed at a lower level appears through the grid spaces of the ink coating of the relief structure disposed at a higher level,
wherein the relief structures and the ink coating form non-diffractive micromirror arrangements with directional micromirrors.

2. The security element according to claim 1 , wherein the grid elements and grid spaces of the grid have the same shape and the same size.

3. The security element according to claim 1 , wherein the area coverage of the grid by the grid elements is between 30% and 70%.

4. The security element according to claim 3 , wherein the area coverage of the grid and the brightness of the ink coatings are matched to one another in order to produce, when viewed, substantially the same brightness of the ink coating of the relief structure disposed at a higher level and the ink coating of the relief structure disposed at a lower level that appears through the grid spaces.

5. The security element according to claim 1 , wherein the dimensions of the grid elements and/or the grid spaces in one or both lateral directions are between 20 μm and 140 μm.

6. The security element according to claim 1 , wherein at least in a part of the feature region either the ink coating of the relief structure disposed at a higher level or the ink coating of the relief structure disposed at a lower level appears for the viewer, depending on the viewing angle,
wherein in a different part of the feature region both ink coatings are visible at the same time for the viewer from at least one viewing angle.

7. The security element according to claim 1 , wherein the two relief structures, depending on the viewing angle,
show a color change for an unchanged motif; or
show a color change together with a motif change,
wherein a motif change of the two relief structures includes differences with regard to shape, movement and/or three-dimensionality of a respective motif.

8. The security element according to claim 1 , wherein the relief structure disposed at a higher level produces a first motif with a first color impression, which is visible from a first viewing angle range, and the relief structure disposed at a lower level produces a second motif with a second, different color impression, which is visible from a second viewing angle range,
wherein the first and second viewing angle ranges do not overlap.

9. The security element according to claim 1 , wherein the relief structure disposed at a higher level produces a first movement motif with a first color impression and the relief structure disposed at a lower level produces a second movement motif with a second, different color impression,
wherein, when the security element is tilted, the first and the second movement motif
move in a manner offset to one another or in a manner against one another and, in an overlap position in which both movement motifs are visible, cross each other and/or
move consecutively through the same part of the feature region.

10. The security element according to claim 1 , wherein the reflective areal region includes exactly two relief structures, each of which is arranged at a specific height level defined along the z direction.

11. The security element according to claim 1 , wherein the relief structures are each characterized by a maximum pitch and a difference between adjacent height levels in the z direction is greater than the maximum pitch of the relief structure disposed at a lower level.

12. The security element according to claim 1 , wherein the ink coatings are formed by glazing inks, by metallizations, thin-film structures, by glazing inks backed with a metallization, by luminescent inks with a metallic mirroring, by structural inks and/or by nanoparticle inks.

13. The security element according to claim 1 , wherein in the feature region there is additionally provided at least one partial region with a negative marking, in which gaps are present in the ink coating of the relief structure disposed at a higher level and at least partially also the ink coating of the relief structure disposed at a lower level.

14. The security element according to claim 13 , wherein the ink coating of the relief structure disposed at a lower level is completely absent in the at least one partial region, so that the negative marking does not produce any of the color impressions of the two ink coatings.

15. The security element according to claim 13 , wherein the ink coating of the relief structure disposed at a lower level is configured to be multilayered, and at least one of the several layers is absent in the at least one partial region, so that a colored negative marking is created.

16. The security element according to claim 1 , wherein each grid element corresponds to exactly one directional micromirror or several directional nano mirrors or micromirrors.

17. A data carrier with an optically variable security element according to claim 1 .

18. A method for manufacturing an optically variable security element with a multicolored, reflective areal region, the method comprising:
providing a carrier, a surface expansion of which defines a z direction standing perpendicularly thereon,
and supplying the carrier with a multicolored, reflective areal region which includes at least two relief structures separated by a top-coat layer or a transparent embossing lacquer layer, the two relief structures arranged at different height levels in the z direction,
wherein the relief structures are each supplied with an ink coating which produce a different color impression,
the two relief structures configured to overlap in a feature region,
wherein the ink coating of the relief structure disposed at a higher level is configured in the feature region as a regular or irregular grid with grid elements and grid spaces, and
wherein the dimensions of the grid elements and/or grid spaces at least in one direction are below 140 μm, so that, in the feature region, for a viewer from at least one viewing angle, the ink coating of the relief structure disposed at a lower level appears through the grid spaces of the ink coating of the relief structure disposed at a higher level,
wherein the relief structures and the ink coating form non-diffractive micromirror arrangements with directional micromirrors.

19. The method according to claim 18 , wherein the optically variable security element is separated from the carrier.

20. An optically variable security element, the surface expansion of which defines a z direction standing perpendicularly thereon, with a multicolored, reflective area

Assignees

• Giesecke & Devrient Currency Technology Gmbh

Inventors

• Scherer Kai Hermann
• Scherer Maik Rudolf Johann
• Dehmel Raphael
• Rahm Michael
• Dorff Giselher
• Rauch Andreas
• Fuhse Christian
• Sattler Tobias

Classifications

• B42D25/324 Primary

  Reliefs · CPC title

• B42D25/351

  Translucent or partly translucent parts, e.g. windows · CPC title

• B42D25/44

  using mechanical means, e.g. engraving · CPC title

• B42D25/36

  comprising special materials · CPC title

• B42D25/445

  using chemical means, e.g. etching · CPC title