Security document including a transparent window formed in the substrate thereof

Patent metadata

Field	Value
Publication number	US-12269286-B2
Application number	US-202318698854-A
Country	US
Kind code	B2
Filing date	Apr 6, 2023
Priority date	May 5, 2022
Publication date	Apr 8, 2025
Grant date	Apr 8, 2025

Abstract

A security document includes a substrate having a transparent window formed in the substrate. A micro-optical structure including microlenses is arranged on one side of the substrate. A first print image is arranged on the other side of the substrate, opposite the micro-optical structure, and includes image elements having a dot size or line thickness smaller than a lens width of the microlenses. A layer is arranged on part of the first print image on the side facing away from the micro-optical structure. A second print image is arranged on the layer, facing away from the micro-optical structure, and so that the second print image can be brought into alignment with the micro-optical structure after folding the substrate at a bending line so that the second print image, or at least a piece of information contained therein, becomes visible and/or recognizable when viewed from a direction of the micro-optical structure.

First claim

The invention claimed is:

1. A security document comprising:
a substrate having a transparent window formed in the substrate;
a micro-optical structure composed of microlenses being arranged on a first side of the substrate, at least in a region of the transparent window, and a first print image being arranged on a second side of the substrate, located opposite the micro-optical structure, at least in the region of the transparent window;
the first print image including a plurality of image elements in a punctiform or linear grid;
a dot size or a line thickness of the image elements being smaller than a lens width of the microlenses arranged in the micro-optical structure;
a layer being arranged on and covering a part of the first print image, on a side of the first print image facing away from the micro-optical structure; and
a second print image being arranged on the layer covering the part of the first print image, on a side of the layer facing away from the micro-optical structure,
wherein the second print image is arranged on the layer covering the part of the first print image in such a way that the second print image can be brought into alignment with the micro-optical structure arranged on the first side of the substrate after carrying out a folding process at a bending line, in such a way that the second print image, or at least a piece of information contained therein, becomes visible and/or recognizable when viewed through the micro-optical structure, and
wherein the bending line is arranged in a part of the first print image which is not covered by the layer arranged on and covering the part of the first print image.

2. The security document according to claim 1 , wherein the image elements of the first print image are made in at least one hue different from white, wherein the layer covering the part of the first print image is made of a lighter hue than the at least one hue different from white of which the image elements of the first print image are made.

3. The security document according to claim 1 , wherein the bending line is arranged so as to be spaced apart from the layer covering the part of the first print image.

4. The security document according to claim 1 , wherein the first print image arranged on the second side of the substrate located opposite the micro-optical structure is created in an offset printing method.

5. The security document according to claim 1 , wherein the layer covering the part of the first print image is created in an ink jet printing method.

6. The security document according to claim 1 , wherein the layer covering the part of the first print image is created in an offset printing method.

7. The security document according to claim 1 , wherein the layer covering the part of the first print image is created in a screen printing method.

8. The security document according to claim 1 , wherein the first print image arranged on the second side of the substrate is composed of an overprint or a superposition of a plurality of print image segments that are each printed in differing printing colors.

9. The security document according to claim 1 , wherein a plurality of the image elements of the first print image arranged under the micro-optical structure are designed so as to belong to different print motifs.

10. The security document according to claim 1 , wherein:
the micro-optical structure is designed as a lens array or as a lenticular lens,
the lens array or the lenticular lens is composed of plano-convex microlenses,
when the micro-optical structure is the lens array, the plano-convex microlenses have at least one of a rotationally symmetric, spheric, or aspheric configuration, and
when the micro-optical structure is the lenticular lens, the plano-convex microlenses have an axially symmetric, rod-shaped configuration.

11. The security document according to claim 1 , wherein the substrate is a fibrous print substrate or a polymer film.

12. The security document according to claim 1 , wherein the security document is designed as a bank note.

13. A security document comprising:
a substrate having a transparent window formed in the substrate;
a micro-optical structure composed of microlenses being arranged on a first side of the substrate, at least in a region of the transparent window, and a first print image being arranged on a second side of the substrate, located opposite the micro-optical structure, at least in the region of the transparent window;
the first print image including a plurality of image elements in a punctiform or linear grid;
a dot size or a line thickness of the image elements being smaller than a lens width of the microlenses arranged in the micro-optical structure;
a layer being arranged on and covering a part of the first print image, on a side of the first print image facing away from the micro-optical structure; and
a second print image being arranged on the layer covering the part of the first print image, on a side of the layer facing away from the micro-optical structure,
wherein the second print image is arranged on the layer covering the part of the first print image in such a way that the second print image can be brought into alignment with the micro-optical structure arranged on the first side of the substrate after carrying out a folding process at a bending line, in such a way that the second print image, or at least a piece of information contained therein, becomes visible and/or recognizable when viewed through the micro-optical structure, and
wherein:
the micro-optical structure is designed as a lens array or as a lenticular lens,
the lens array or the lenticular lens is composed of plano-convex microlenses,
when the micro-optical structure is the lens array, the plano-convex microlenses have at least one of a rotationally symmetric, spheric, or aspheric configuration, and
when the micro-optical structure is the lenticular lens, the plano-convex microlenses have an axially symmetric, rod-shaped configuration.

Assignees

• Koenig & Bauer Ag

Inventors

• Crassous Arnaud
• Stewart Robert
• Stierman Robert

Classifications

• B42D25/351

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

• B42D25/29 Primary

  Securities; Bank notes · CPC title

• B41F19/08

  Simultaneous moulding and printing · CPC title

• B41F19/001

  with means for coating or laminating · CPC title

• B41F19/007

  with selective printing mechanisms, e.g. ink-jet or thermal printers · CPC title