Method and device for examining value documents for irregularities

Patent metadata

Field	Value
Publication number	US-10049522-B2
Application number	US-201415021798-A
Country	US
Kind code	B2
Filing date	Sep 11, 2014
Priority date	Sep 13, 2013
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

A means and method for checking a value document of at least one irregularity of at least one specified type, in which an ultrasound data record is captured which describes in locally resolved fashion at least one ultrasound property, a deviation data record is ascertained which describes in locally resolved fashion a deviation between the ultrasound data record and a model and is ascertained such that the deviation described thereby is minimal with respect to the model. The model comprises a model for the location dependence of the at least one ultrasound property of reference value documents of the specified value document type without irregularities of the at least one specified type, and using the deviation data record, it is checked whether an indication of an irregularity of the at least one type is present on the value document.

First claim

The invention claimed is:

1. A method for checking a value document of a specified value document type for a presence of at least one irregularity of at least one specified type, in which
an ultrasound data record is captured, which describes in locally resolved fashion at least one ultrasound property, of the value document;
a deviation data record is ascertained, which describes in locally resolved fashion a deviation between an ultrasound data record and a model and is ascertained such that the deviation described thereby is minimal with respect to the model, wherein the model comprises a model for location dependence of the at least one ultrasound property of reference value documents of the specified value document type without irregularities of the at least one specified type, wherein the model defines a plurality of model data records differing from each other, which describe the at least one ultrasound property in location-dependent fashion; and
using the deviation data record, checking whether an indication of an irregularity of the at least one specified type is present on the value document.

2. The method according to claim 1 , in which the ultrasound data records respectively include ultrasound data for a number N of places which is specified for the value document type, which data respectively describe the at least one ultrasound property for the respective places, and in which the model data records respectively include model data for the at least one ultrasound property for the specified number N of places and lie in a specified partial region of an N-dimensional space of possible ultrasound data.

3. The method according to claim 2 , in which the partial region is specified such that model data records are representable, upon a representation of the ultrasound data record and the model data records as vectors of the same dimension, by a sum of a mean vector and a linear combination of at least five specified partial-region vectors.

4. The method according to claim 3 , in which the mean vector and the partial-region vectors are obtainable, or obtained by analysis of reference ultrasound data records for specified reference value documents of the specified value document type without irregularities of the at least one specified type.

5. The method according to claim 4 , in which the analysis comprises a main component analysis, wherein a mean value ascertained upon the main component analysis corresponds to the mean vector and the main components ascertained upon the main component analysis correspond to the partial-region vectors.

6. The method according to claim 2 , in which the model has a statistical model distribution which describes a probability of the occurrence of model data records.

7. The method according to claim 2 , in which at least one feature is ascertained for the deviation data record, and upon checking whether an indication of an irregularity of the at least one specified type is present on the value document the at least one feature is employed, or in which at least two features are ascertained for the deviation data record, and upon checking whether an indication of an irregularity of the at least one specified type is present on the value document the at least two features are employed.

8. The method according to claim 6 , in which at least one feature is ascertained for the deviation data record, and upon checking whether an indication of an irregularity of the at least one specified type is present on the value document the at least one feature is employed, or in which at least two features are ascertained for the deviation data record, and upon checking whether an indication of an irregularity of the at least one specified type is present on the value document the at least two features are employed.

9. The method according to claim 7 , in which the feature or one of the features describes a probability that the ultrasound data record or the deviation data record or the model data records corresponding to the deviation data record occurs according to the model.

10. The method according to claim 7 , in which the feature or one of the features describes a quantity of the deviation described by the deviation data record.

11. The method according to claim 7 , in which the feature or one of the features represents a measure for a magnitude of deviations at places at which a difference between ultrasound transmission and model, ascertainable from deviation data of the deviation data record, indicates an irregularity of the at least one specified type.

12. The method according to claim 7 , in which the feature or one of the features represents a measure of places, for which deviation data of the deviation data record indicate an irregularity of the at least one specified type, occurring spatially cumulated, and that upon ascertaining the measure also the quantities of deviations are taken into account.

13. The method according to claim 7 , in which the feature or one of the features represents a measure for a presence of deviations at places for which deviation data of the deviation data record indicate an irregularity of the at least one specified type, along a line of a specified form.

14. The method according to claim 7 , in which upon checking whether an indication of an irregularity of the at least one specified type is present on the value document a classification is carried out by means of a support vector machine, using the at least one feature or the features.

15. The method according to claim 8 , in which upon checking whether an indication of an irregularity of the at least one specified type is present on the value document a classification is carried out by means of a support vector machine, using the at least one feature or the features.

16. The method according to claim 1 , in which irregularities of the at least one specified type comprise irregularities of the type of an adhesion, and/or irregularities of the crease type.

17. The method according to claim 1 , in which irregularities of the at least one specified type comprise irregularities of the type of a material removal.

18. An apparatus for checking a value document of a specified value document type for a presence of at least one irregularity of at least one specified type, having an evaluation device which is configured for executing the method according to claim 1 , and in particular for
capturing an ultrasound data record which describes in locally resolved fashion at least one ultrasound property, an ultrasound transmission, of the value document;
ascertaining a deviation data record which describes in locally resolved fashion a deviation between the ultrasound data record and a model and is ascertained such that the deviation described thereby is minimal with respect to the model, wherein the model comprises a model for a location dependence of the at least one ultrasound property of reference value documents of the specified value document type without irregularities of the at least one specified type and defines a plurality of model data records differing from each other which describe the at least one ultrasound property in location-dependent fashion; and
using the deviation data record, checking whether an indication of at least one irregularity of the at least one specified type is present on the value document.

19. The apparatus according to claim 18 , which further has an ultrasound sensor for a locally resolved measurement of the at least one ultrasound property of a value document and formation of an ultrasound data record for the va

Assignees

• Giesecke & Devrient Gmbh
• Giesecke & Devrient Currency Technology Gmbh

Inventors

• Feulner Johannes
• Domke Jan

Classifications

• G01N29/04

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• G07D7/183

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• G01N29/11

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• G07D7/08 Primary

  Acoustic waves · CPC title

• G07D7/182

  Testing stiffness · CPC title