Method for inspecting at least one copy of a printed product

Patent metadata

Field	Value
Publication number	US-9256931-B2
Application number	US-201314420676-A
Country	US
Kind code	B2
Filing date	Jun 27, 2013
Priority date	Aug 24, 2012
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

A method is used for inspecting at least one copy of a printed product. At least one element, which is spatially constant with respect to a fixed reference point and at least one element which is spatially variant with respect to the same fixed reference point are reliably inspected by reference image data being used for a desired-actual value comparison of the at least one spatially variant element. The reference image data takes account of the variable position of the at least one element; i.e. the spatial variance thereof.

First claim

What is claimed is:

1. A method for inspecting at least one copy of a printed product, including:
producing at least one first copy of said printed product and at least one second copy of the same printed product in a printing process using a printing machine;
providing an inspection system having an image capturing device;
generating a photographic image of the at least one first copy of the printed product using said image capturing device of the inspection system;
providing a learning phase of the inspection system, which learning phase precedes the inspecting of the at least one second copy of the printed product, and using the generated photographic image of the at least one first copy of the printed product, during a subsequent inspection phase;
separating, during said learning phase, a first photographic image of at least one first element of the at least one first copy of the printed product and which is spatially variant with regard to a reference point that is fixed for the at least one first copy of the printed product, from a second photographic image, contained in the same generated photographic image of the at least one first copy of the printed product, of at least one element and which is spatially constant with regard to the same fixed reference point;
using the first photographic image of the at least one spatially variant element obtained from the generated photographic image of the at least one first copy of the printed product as a first reference image for the at least one spatially variant element;
using the second photographic image of the at least one spatially constant element obtained from the same generated photographic image of the at least one first copy of the printed product as a second reference image for the at least one spatially constant element;
generating, during the inspection phase of the inspection system, a photographic image of the at least one second copy of the printed product by using the image capturing device of the inspection system;
separating, from the photographic image generated during the inspection of the at least one second copy of the printed product, a third photographic image of at least one element which is spatially variant with regard to a reference point that is fixed for the at least one second copy of the printed product from a fourth photographic image, contained in the same generated photographic image of the at least one second copy of the printed product, of at least one element which is spatially constant with regard to the same fixed reference point;
providing first and second storage devices for said first and second reference images;
comparing the third photographic image of the at least one spatially variant element, contained in the generated photographic image of the at least one second copy of the printed product with the first reference image obtained from the at least one first copy of the printed product and corresponding to the at least one spatially variant; and
comparing the fourth photographic image of the at least one spatially constant element, contained in the generated photographic image of the at least one second copy of the printed product with the respective second reference image obtained from the at least one first copy of the printed product and corresponding to the at least one spatially constant element.

2. The method according to claim 1 , further including separating the first photographic image of the at least one element which is spatially variant with regard to the fixed reference point from the second photographic image of the at least one element which is spatially constant with regard to the fixed reference point and which is contained in the same generated photographic image of the one of the first and second copy of the printed product using one of a filter and a filtering process.

3. The method according to claim 1 further including storing, during the learning phase and following the separation step, the at least one photographic image of the at least one element which is spatially variant with regard to the fixed reference point in the first storage device as the first reference image that corresponds to the at least one spatially variant element, and storing at least one photographic image of the at least one element which is spatially constant with regard to the fixed reference point in the second storage device as the second reference image that corresponds to the at least one spatially constant element.

4. The method according to claim 1 , further including, in at least one of the at least one first copy of the printed product and in the at least one second copy of the printed product, carrying out a position correction for at least one of the at least one photographic image of the at least one element which is spatially constant with regard to the fixed reference point and for the respective at least one photographic image of the at least one element which is spatially variant with regard to the fixed reference point, and further including calculating a motion vector, for each of an anticipated and acknowledged change in a position of the respective elements for compensating for the one of an anticipated and acknowledged change in position in the image.

5. The method according to claim 4 further including carrying out the compensation for the one of the anticipated and acknowledged change in position in the at least one first copy of the printed product before the reference image is stored in one of the first and second storage devices.

6. The method according to claim 4 further including carrying out the compensation for the one of the anticipated and acknowledged change in position in the at least one second copy of the printed product before carrying out the comparison with the reference image.

7. The method according to claim 1 further including providing a control unit and using the control unit for carrying out the separation of at least one of the photographic image of the at least one first copy of the printed product and the separation of the photographic image of the at least one second copy of the printed product.

8. The method according to claim 4 further including providing a control unit and using the control unit for carrying out the execution of the at least one of the position correction and a storage of the respective reference image in one of the first and second storage devices.

9. The method according to claim 1 further including carrying out the separation of the photographic image of the at least one first copy of the printed product and the separation of the photographic image of the at least one second copy of the printed product in real time.

10. The method according to claim 1 further including carrying out the execution of the one of the position correction and the storage of the respective reference image in one of the first and second storage devices in real time.

11. The method according to claim 1 further including providing a control unit and using that control unit for enlarging a standard frame of the image capturing device which serves to capture the image in at least one direction that lies within an image capturing plane of the image capturing device.

12. The method according to claim 1 further including using one of an edge of the copy of the printed product and the center thereof as the fixed reference point of the copy of the printed product.

13. The method according to claim 1 further including using the method for inspecting at least one copy of a printed product in at least one of security printing and package printing.

14. The method according to claim 1 further including pro

Assignees

• Koenig & Bauer Ag
• Koenig & Bauer Ag

Inventors

• Bless Stefan
• Diederichs Carsten
• Hartmann Felix
• Sacher Jorn

Classifications

• G06T7/001 Primary

  using an image reference approach · CPC title

• G06T2207/30168

  Image quality inspection · CPC title

• B41F33/0081

  Devices for scanning register marks · CPC title

• B41F11/02

  for securities (security printing B41M3/14) · CPC title

• G06T2207/20081

  Training; Learning · CPC title