Security devices and methods of manufacture thereof

Patent metadata

Field	Value
Publication number	US-12187064-B2
Application number	US-202118026067-A
Country	US
Kind code	B2
Filing date	Sep 10, 2021
Priority date	Sep 11, 2020
Publication date	Jan 7, 2025
Grant date	Jan 7, 2025

Abstract

A security device is disclosed, including: a substrate having opposing first and second surfaces; on the first surface of the substrate, a surface relief structure formed of one or more cured, at least semi-transparent material(s); and on the second surface of the substrate, a print layer. In at least a first region of the security device in at least part of which the substrate is transparent or translucent, the surface relief structure and the print layer are each defined in accordance with a common image and are in alignment with one another, the surface relief structure exhibiting a first set of feature(s) of the common image and the print layer exhibiting a second set of feature(s) of the common image. The common image is exhibited by the surface relief structure and the print layer in combination with one another and the surface relief structure provides tactility to the common image.

First claim

The invention claimed is:

1. A security device, comprising:
a substrate having opposing first and second surfaces;
on the first surface of the substrate, a surface relief structure formed of one or more cured, at least semi-transparent material(s); and
on the second surface of the substrate, a print layer;
wherein, in at least a first region of the security device in at least part of which the substrate is transparent or translucent, the surface relief structure and the print layer are in alignment with one another, the surface relief structure exhibiting a first set of feature(s) of a common image and the print layer exhibiting a second set of feature(s) of the common image, whereby the common image is exhibited by the surface relief structure and the print layer in combination with one another and the surface relief structure provides tactility to the common image, the common image being a static macro-image, and
wherein the surface relief structure includes a plurality of spaced protrusions, joined to one another by a base layer of lesser height.

2. A security device according to claim 1 , wherein the first and second sets of feature(s) are identical to one another, the surface relief structure and the print layer each exhibiting all the features of the common image.

3. A security device according to claim 1 , wherein the first and second sets of feature(s) are different from one another, the first set of feature(s) and/or the second set of feature(s) being a subset of the features of the common image.

4. A security device according to claim 1 , wherein the first set of feature(s) corresponds to a first colour component of the common image, and the second set of feature(s) corresponds to at least a second colour component of the common image.

5. A security device according to claim 1 , wherein either:
the first set of feature(s) of the common image, exhibited by the surface relief structure, is laterally located wholly within a boundary of the second set of feature(s) of the common image, exhibited by the print layer; and/or
the second set of feature(s) of the common image, exhibited by the print layer, is laterally located wholly within a boundary of the second set of feature(s) of the common image exhibited by the surface relief structure.

6. A security device according to claim 1 , wherein the common image is defined at least in part by an array of image elements spaced from one another, and either:
the surface relief structure comprises a plurality of raised elements spaced from one another which form the image elements defining the first set of feature(s) of the common image; and/or
the print layer comprises a plurality of print elements spaced from one another which form the image elements defining the second set of feature(s) of the common image.

7. A security device according to claim 6 , wherein the common image is a screened image, the image elements varying across the array in terms of their size, shape, colour, optical density and/or spacing in order to convey the common image.

8. A security device according to claim 1 , wherein the common image is a multi-tonal and/or multi-coloured image.

9. A security device according to claim 1 , wherein the at least one curable material is colourless and the print layer exhibits one or multiple visible colour(s).

10. A security device according to claim 1 , wherein the at least one curable material carries a tint of a first colour and the print layer exhibits at least the first colour and/or a second colour.

11. A security device according to claim 1 , wherein the at least one curable material carries a tint of at least one colour and the print layer has a visual opacity such that a colour appearance of the common image is different when the security device is viewed from a surface relief structure side of the security device as compared with when viewed from a print layer side of the security device.

12. A security device according to claim 1 , wherein the substrate is transparent or translucent across the first region of the security device.

13. A plurality of substantially identical security devices, each in accordance with claim 1 , in each of which the respective surface relief structures and print layers have a same position relative to one another.

14. A security document comprising a document substrate and a security device thereon, the security device being in accordance with claim 1 , wherein the document substrate may or may not act as the substrate of the security device.

15. A method of manufacturing a security device, comprising, in any order or simultaneously:
forming a surface relief structure on a first surface of a substrate from one or more at least semi-transparent curable material(s); and
printing a print layer onto a second surface of the substrate,
wherein, in at least a first region of the security device in at least part of which the substrate is transparent or translucent, the surface relief structure and the print layer are in alignment with one another, the surface relief structure exhibiting a first set of feature(s) of a common image and the print layer exhibiting a second set of feature(s) of the common image, whereby the common image is exhibited by the surface relief structure and the print layer in combination with one another and the surface relief structure provides tactility to the common image, wherein the common image is a static macro-image, and
wherein the surface relief structure includes a plurality of spaced protrusions, joined to one another by a base layer of lesser height.

16. A method according to claim 15 , wherein the formation of the surface relief structure and the printing of the print layer are performed in register with one another.

17. A method according to claim 16 , wherein the formation of the surface relief structure and the printing of the print layer are simultaneous, taking place at a same position along the machine direction, at a same time.

18. A method according to claim 15 , wherein forming the surface relief structure comprises cast-curing one or more at least semi-transparent curable material(s) on the first surface of the substrate by:
providing a casting tool having a mould relief defined therein corresponding to the surface relief structure;
applying the one or more at least semi-transparent curable material(s) to the casting tool or to the substrate;
bringing the casting tool and the substrate into contact with the one or more at least semi-transparent curable material(s) therebetween, to thereby form the one or more at least semi-transparent curable material(s) into the surface relief structure; and
during and/or after the contact, curing the one or more at least semi-transparent curable material(s) so as to retain the surface relief structure.

Assignees

• De La Rue Int Ltd

Inventors

• Godfrey John
• Locke Rebecca

Classifications

• B41P2200/10

  Relief printing · CPC title

• B41M3/148

  Transitory images, i.e. images only visible from certain viewing angles · CPC title

• B42D25/425

  by deformation, e.g. embossing · CPC title

• B42D25/351

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

• B42D25/387

  absorbing or reflecting ultraviolet light · CPC title