Kba-notasys Sa

Koenig & Bauer-aktiengesellschaft

Bernd Stöber

Volker Lohweg

Johannes Georg Schaede

Volkmar Rolf Schwitzky

Günther Hoier

Harald Willeke

Thomas Türke

Carsten Diederichs

Stefan Budach

Jörn Sacher

Thomas Hochrein

A method for controlling the quality of printed documents, such as banknotes, in which only part of the surface of the printed documents is available for inspection, comprising the steps of (i) storing a reference image; (ii) acquiring a sample image of a sample printed document to be controlled, which sample image covers only a limited portion of the sample printed document; (iii) selecting a search pattern within the acquired sample image; (iv) searching the reference image for a match with the selected search pattern, (v) determining control parameters linked to the position of the search pattern within said sample image and within said reference image, (vi) comparing the control parameters linked to the position of the search pattern within the sample image with the control parameters linked to the position of the search pattern within the reference image; and (vii) based on the results of the comparison of the control parameters, accepting or rejecting the sample printed document.

Method for controlling the quality of printed documents based on pattern matching

There is described a sheet inspection system for a sheet-fed recto-verso printing press of the type comprising two printing cylinders () for carrying out simultaneous recto-verso printing of the sheets, said sheet inspection system comprising at least a first inspection device () for taking an image of a first side of the printed sheets. The first inspection device () comprises a first line image sensor () for performing line-scanning image acquisition of the first side of the printed sheets, and the first inspection device () is disposed in such a way that the first line image sensor visually acquires an image of a printed sheet while the said printed sheet is still adhering onto the surface of a first one () of the two printing cylinders () of the printing press and immediately before the said printed sheet is transferred to a chain gripper system () of the printing press. Also described is a printing press equipped with the inspection system.

Inspection system for a sheet-fed recto-verso printing press

There is described a sheet inspection system for a sheet-fed recto-verso printing press of the type comprising two printing cylinders () for carrying out simultaneous recto-verso printing of the sheets, said sheet inspection system comprising at least one inspection device () for taking an image of one side of the printed sheets. The sheet inspection system comprises first and second transfer cylinders () interposed between a first () of the two printing cylinders () and a chain gripper system () of the printing press, printed sheets being transferred successively from the first printing cylinder () to the first transfer cylinder (), to the second transfer cylinder (), and to the chain gripper system (). The inspection device () comprises a line image sensor () for performing line-scanning image acquisition of the one side of the printed sheets, this line image sensor () visually acquiring an image of a printed sheet while the printed sheet is being transported on the first or second transfer cylinder ().

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Rheda-Wiedenbrück, Germany

Bernd Stöber