Optical detection method during print finishing
AssigneeFerag AG
InventorCarl Conrad Mäder
Life of this patent
Estimating the term…
Abstract
An optical control method for use in print finishing, comprising the following steps: First, guiding a planar printed product along a conveying path past at least one optical sensor (14). Secondly, detecting an electronic image (2) by the optical sensor, wherein the electronic image (2) comprises at least one region of the printed product. Third, extracting orientation information of the printed product from the electronic image. Fourth, comparing (51) the orientation information of the printed product from the electronic image with reference orientation information, and generating at least one signal on the basis of a result of the comparison.
Claims16
An optical control method for use in print finishing, comprising:
- guiding a planar printed product along a conveying path past at least one optical sensor;
- capturing an electronic image by use of the at least one optical sensor, wherein the electronic image represents at least one region of the printed product;
- extracting orientation information from the electronic image using a frequency transformation of the electronic image, said orientation information reflective of an orientation of the printed product;
- comparing the orientation information of the printed product from the electronic image with reference orientation information based on a first correlation, wherein the reference orientation information is based on a frequency transformation of a reference image;
- and
- generating at least one signal that reflects a result of the comparison,
- wherein the at least one signal comprises a first signal, which initiates a special treatment of the printed product on which the electronic image is based, if a correlation value of the first correlation falls below a first threshold value,
- wherein a rotation angle between the controlled printed product and the reference printed product together with direction information is calculated on the basis of the orientation information and the reference orientation information, and
- wherein the electronic image is rotated back by the rotating angle in such a way that the printed product imaged thereon has the same orientation as the reference printed product.
An apparatus for carrying out an optical control method, the apparatus comprising:
- at least one optical sensor for capturing electronic images of printed products;
- a conveyor for transporting the printed products past the at least one optical sensor;
- and
- an image processing system configured to (1) extract orientation information of a printed product from the electronic image using a frequency transformation of the electronic image and (2) compare the extracted orientation information with reference orientation information based on a first correlation, which reference orientation information reflects a frequency transformation of a reference image, and (3) generate at least one signal that reflects a result of the comparison,
- wherein the at least one signal comprises a first signal, which initiates a special treatment of the printed product on which the electronic image is based, if a correlation value of the first correlation falls below a first threshold value,
- wherein a rotation angle between the controlled printed product and the reference printed product together with direction information is calculated on the basis of the orientation information and the reference orientation information, and
- wherein the electronic image is rotated back by the rotating angle in such a way that the printed product imaged thereon has the same orientation as the reference printed product.
Dependencies are inferred from the claim text.