Verification of a security document

Patent metadata

Field	Value
Publication number	US-11068681-B2
Application number	US-201716470019-A
Country	US
Kind code	B2
Filing date	Dec 13, 2017
Priority date	Dec 16, 2016
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

A method for verifying a security document by means of a reading device wherein first transmission and/or reflection properties of a first region of the security document are detected in a first spectral range by the reading device and a first data set specifying these properties is generated therefrom, wherein the first region at least in some regions overlaps an optical security element arranged on the security document or embedded in the security document and wherein second transmission and/or reflection properties of the first region of the security document are detected in a second spectral range by the reading device and a second data set specifying these properties is generated therefrom, wherein the first spectral range differs from the second spectral range, and wherein, the authenticity of the security document and/or of the security element is checked on the basis of at least the first data set and the second data set.

First claim

The invention claimed is:

1. A method for verifying a security document by means of a reading device wherein first transmission and/or reflection properties of a first region of the security document are detected in a first spectral range by the reading device and a first data set specifying these properties is generated therefrom, wherein the first region at least in some regions overlaps an optical security element arranged on the security document or embedded in the security document and wherein second transmission and/or reflection properties of the first region of the security document are detected in a second spectral range by the reading device and a second data set specifying these properties is generated therefrom, wherein the first spectral range differs from the second spectral range, and wherein the authenticity of the security document and/or of the security element is checked on the basis of the first data set and the second data set,
wherein a threshold image is calculated from the first data set and a threshold image is calculated from the second data set, and
wherein, in each case, the following steps are carried out to calculate the threshold image from the allocated data set:
calculation of an edge image from the allocated data set;
calculation of a black image from the allocated data set;
calculation of a white image from the allocated data set; and
calculation of the threshold image by combining the edge image, the black image and the white image, and

wherein the following steps are carried out to determine the black image:
comparison of the lightness values of the image point data of the allocated data set with a first threshold value, wherein all image points which lie below the first threshold value are allocated the binary value 0.

2. The method according to claim 1 , wherein an item of information about the authenticity, of the security element or of the security document is output by the reading device.

3. The method according to claim 1 , wherein third and/or fourth transmission and/or reflection properties of the first region of the security document are detected in a third spectral range or in a fourth spectral range by the reading device and a third data set or fourth data set specifying these properties is generated therefrom, wherein the third spectral range or the fourth spectral range differs from the first spectral range and second spectral range, wherein the authenticity of the security document and/or of the security element is checked on the basis of at least the first, the second, the third data set and/or the fourth data set.

4. The method according to claim 3 , wherein the first, second, third and/or fourth transmission and/or reflection properties of the first region of the security document are detected in the first, second, third and/or fourth spectral range by the reading device from sides of the front side in reflected light, from sides of the rear side in reflected light and/or in transmitted light and the first, second, third or fourth data set specifying these properties is generated therefrom, wherein at least one of the first detected data sets contains data about the reflection properties in reflected light from the front and/or rear side, data about the reflection properties in reflected light from the front and/or rear side and in transmitted light, and the authenticity of the security document and/or security element is checked on the basis of these data of this data set.

5. The method according to claim 3 , wherein the first, second, third and/or fourth spectral range is selected from the group: IR range of the electromagnetic radiation, in particular from a wavelength range of from 850 nm to 950 nm, VIS range of the electromagnetic radiation from a wavelength range of from 400 nm to 700 nm, and UV range of the electromagnetic radiation, from a wavelength range of from 1 nm to 400 nm.

6. The method according to claim 1 , wherein the security element of the security document has one or more security features in the first region, and/or wherein the security document in the first region has one or more security features, wherein the security features overlap at least in some regions.

7. The method according to claim 1 , wherein the following steps are carried out to check the authenticity of the security document determination of one or more relative values, of two or more security features of the security element and/or of the security document relative to each other by means of the comparison of at least the first data set and the second data set, comparison of the determined one or more relative values of the two or more security features with allocated reference values and denial of the authenticity if the deviation lies outside an allocated tolerance range.

8. The method according to claim 1 , wherein to check the authenticity of the security document, the following steps are carried out:
determination of the positional arrangement and/or shaping of a first security feature of the security element by means of the first data set,
determination of the positional arrangement and/or shaping of a second security feature of the security element and/or of the security document by means of the second data set, and
comparison of the determined positional arrangements and/or shaping with each other to determine the relative positional arrangement, of two or more security features of the security element relative to each other or of image elements of two or more of the security features.

9. The method according to claim 6 , wherein at least one of the security features has one or more image elements and a background region surrounding the image elements, wherein the contrast between image elements and background region in at least one of the first or second spectral ranges in reflected light and/or transmitted light is greater than 5%, and/or the difference in a reflectance and/or a transmittance is greater than 5%.

10. The method according to claim 6 , wherein at least one of the security features has one or more image elements and a background region surrounding the image elements, wherein the contrast between the image elements and the background region in at least one of the first or second spectral ranges in reflected light and/or transmitted light is smaller than 95%.

11. The method according to claim 6 , wherein at least one of the security features is formed by a partially shaped metal layer, which is recognizable under IR illumination.

12. The method according to claim 11 , wherein the metal layer consists of Al, Cu, Cr, Ag, Au or an alloy thereof.

13. The method according to claim 6 , wherein at least one of the security features is formed by a color layer.

14. The method according to claim 13 , wherein the color layer is formed substantially transparent in the first spectral range.

15. The method according to claim 13 , wherein the color layer has a transmittance in the second spectral range and/or in a partial range of the second spectral range of at most 50%.

16. The method according to claim 13 , wherein the color layer is formed or appears luminescent.

17. The method according to claim 13 , wherein the color layer is excited by radiation of the second spectral range.

18. The method according to claim 13 , wherein at least one of the security features is formed by a relief structure and a reflective layer, wherein the relief structure deflects the incident radiation in a predefined manner in at least one of the spectral ranges.

19. The method according to claim 18 , wherein the

Assignees

• Kurz Digital Solutions Gmbh & Co Kg
• Ovd Kinegram Ag

Inventors

• Frieser Uwe
• Grau Michael
• Staub René
• Hoffmann Michael

Classifications

• G07D7/12 Primary

  Visible light, infrared or ultraviolet radiation · CPC title

• G06V10/22

  by selection of a specific region containing or referencing a pattern; Locating or processing of specific regions to guide the detection or recognition · CPC title

• G06K7/1417 Primary

  2D bar codes · CPC title

• G06V10/60

  relating to illumination properties, e.g. using a reflectance or lighting model · CPC title

• G06V10/28

  Quantising the image, e.g. histogram thresholding for discrimination between background and foreground patterns · CPC title