Apparatus and method for checking value documents, in particular bank notes, and value-document processing system

A method for checking value documents, having the following steps:

• capturing an electromagnetic radiation transmitted by a value document and generating corresponding first sensor signals;
• capturing an electromagnetic radiation remitted by the value document and generating corresponding second sensor signals;
• and
• checking whether the value document has a foreign object, taking into account the first and second sensor signals which correspond to the electromagnetic radiation respectively transmitted or remitted in the region of the edge of the value document;
• wherein at least one sensor is configured for generating a transmission image, composed of the first sensor signals, and a remission image composed of the second sensor signals, and
• an evaluation device is configured for
• ascertaining on the basis of the first sensor signals one or more first edge points which correspond to the edge of the value document;
• ascertaining on the basis of the second sensor signals one or more second edge points which correspond to the edge of the value document;
• and
• checking whether the value document has a foreign object on a basis of any differences between an edge course of the value document ascertained from the transmission image and an edge course of the value document ascertained from the remission image.

An assembly for checking value documents comprising:

• at least one sensor for capturing an electromagnetic radiation transmitted by a value document and generating corresponding first sensor signals which correspond to the electromagnetic radiation respectively transmitted in the region of the edge of the value document, and for capturing an electromagnetic radiation remitted by the value document and generating corresponding second sensor signals which correspond to the electromagnetic radiation respectively remitted in the region of the edge of the value document, and
• an evaluation device for checking whether the value document has a foreign object taking into account the first sensor signals and taking into account the second sensor signals;
• wherein the at least one sensor is configured for generating a transmission image, composed of first sensor signals, and a remission image composed of second sensor signals, and
• the evaluation device is configured for
• ascertaining on the basis of the first sensor signals one or more first edge points which correspond to the edge of the value document;
• ascertaining on the basis of the second sensor signals one or more second edge points which correspond to the edge of the value document;
• and
• checking whether the value document has a foreign object on a basis of any differences between an edge course of the value document ascertained from the transmission image and an edge course of the value document ascertained from the remission image.