Device for examining a value document and method for examining a value document

Patent metadata

Field	Value
Publication number	US-9685019-B2
Application number	US-201314648175-A
Country	US
Kind code	B2
Filing date	Dec 10, 2013
Priority date	Dec 10, 2012
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

A method or apparatus for examining a security element of a value document involves at least one optical property of the security element influenceable by a magnetic field. The value document is transported through a magnetic field which is inhomogeneous transversely to the transport direction and/or is changed time-dependently. An image of at least one portion of the value document having the security element is captured and image data describing the image are formed. The optical properties of the security element are influenced by the magnetic field, and the image data is checked whether they have a location dependence transverse to the transport direction corresponding to the location dependence of the magnetic field and/or have a location dependence in the transport direction corresponding to the time dependence of the magnetic field.

First claim

The invention claimed is:

1. An apparatus for examining a security element of a value document, wherein at least one optical property of the security element is changeable by a magnetic field, comprising:
an image capturing device having a capture region, which is configured to capture a locally resolved image of at least one portion of the value document having the security element, while this is transported through the capture region in a specified transport plane in a specified transport direction, and to generate image data describing the image,
a magnetic field-generating device for generating before or in the capture region a magnetic field which is inhomogeneous transversely to the transport direction or variable in time, so that the security element has optical properties which are or have been changed by the magnetic field when it passes the capture region; and
an evaluation device for evaluating the image data, which is configured to check whether those image data, which describe an image region showing the security element, have a location dependence in a direction transverse to the transport direction which corresponds to the location dependence of the magnetic field in a direction transverse to the transport direction or have a location dependence in the transport direction which corresponds to the time dependence of the magnetic field.

2. The apparatus according to claim 1 , in which the magnetic field-generating device is configured such that in the transport plane the direction of the magnetic field in at least some first portions encloses with the transport plane an angle of less than 40°, and in other second portions encloses with the transport plane an angle between 50° and 90°, wherein the first and second portions are alternately arranged transverse to the transport direction.

3. The apparatus according to claim 2 , in which the magnetic field-generating device has at least one permanent magnet or a permanent magnet foil.

4. The apparatus according to claim 3 , in which the magnetic field-generating device has a retainer movable back and forth between a specified number of positions relative to the optical detection device, in which retainer, permanent magnets are arranged such that in each of the positions at least one of the permanent magnets generates a different magnetic field inhomogeneous at least in the transport plane and transverse to the transport direction.

5. The apparatus according to claim 4 , in which the magnetic field-generating device has a coil arrangement with at least one coil for generating a magnetic field and has a driving device which supplies the coil arrangement with current.

6. The apparatus according to claim 5 , in which the driving device is configured such that it supplies the coil arrangement with current pulses such that the coil arrangement is without current at least between two successive value documents.

7. The apparatus according to claim 5 , in which the driving device is configured to supply the coil arrangement with current in such a way that the time-dependent magnetic field is generated.

8. The apparatus according to claim 7 , in which the evaluation device is configured to first ascertain, upon the check, a region for the security element in the image and for the further check of the location dependence the image data describing said region in the image are employed.

9. A method for examining a security element of a value document, wherein at least one optical property of the security element is changeable by a magnetic field, comprising the steps
transporting the value document through a magnetic field which is inhomogeneous transversely to the transport direction or is varied in time whereby the optical properties of the security element are changed by the magnetic field,
capturing an image of at least one portion of the value document comprising the security element and forming image data describing the image and
checking whether those image data, which describe an image region showing the security element, have a location dependence transverse to the transport direction which corresponds to the location dependence of the magnetic field or have a location dependence in the transport direction which corresponds to the time dependence of the magnetic field.

10. The method according to claim 9 , in which in at least some first portions the direction of the magnetic field in the transport plane encloses with the transport plane an angle of less than 40°, and in other second portions encloses with the transport plane an angle between 50° and 90°, wherein the first and second portions are alternately arranged transverse to the transport direction.

11. The method according to claim 9 , in which the magnetic field is generated using at least one permanent magnet or one permanent magnet foil.

12. The method according to claim 9 , in which before the transporting of the value document, a retainer movable back and forth between a specified number of positions, in which retainer, permanent magnets are arranged such that in each of the positions at least one of the permanent magnets generates a different magnetic field inhomogeneous at least in the transport plane and transverse to the transport direction, can be moved from an existing position into a new position.

13. The method according to claim 9 , in which the magnetic field is generated using a coil arrangement with at least one coil for generating a magnetic field.

14. The method according to claim 13 , in which the coil arrangement is supplied with current pulses such that the coil arrangement is without current at least between two successive value documents.

15. The method according to claim 13 , in which the coil arrangement is supplied with current such that the time-dependent magnetic field is generated.

16. The method according to claim 9 , in which upon the check there is first ascertained a region for the security element in the image and the further check of the location dependence is carried out for the image data describing said region in the image.

Assignees

• Giesecke & Devrient Gmbh

Inventors

• Mengel Christoph
• Bornschlegl Alexander
• Schiffmann Peter
• Schutzmann Jurgen

Classifications

• G07D7/12

  Visible light, infrared or ultraviolet radiation · CPC title

• G07D7/124

  Physics · mapped topic

• G07D7/04 Primary

  Testing magnetic properties of the materials thereof, e.g. by detection of magnetic imprint (G07D7/01 takes precedence) · CPC title

• B42D15/00

  Printed matter of special format or style not otherwise provided for · CPC title

• G07D7/003

  using security elements (using digital security elements G07D7/004) · CPC title