Patent ID: 9600952
Date: 2017-03-21
CPC Classifications: G01N,G07D

Claim:
1. A method for checking a value document of a specified value-document type having a window which has a foil region, the method comprising: capturing ultrasound transmission properties using a spatially resolving ultrasound transmission sensor that establishes measurement values for an ultrasound transmission of the value document in a spatially resolved manner; defining a specified outside portion which lies outside of a checking region of the value document, the outside portion comprising some, but not all of, the value document; checking, while employing the measurement values, whether for a specified number of locations in the specified checking region of the value document the ultrasound transmission according to a specified criterion is greater than a specified minimum ultrasound transmission that is characteristic of the specified outside portion of the value document; and as a result of the checking, generating a signal describing the result of the checking.