Device for trimming and automatic cutting of images on paper and other graphic and photographic substrates, in particular of large size

A device for trimming and automatically cutting images (10a, 10b, 10c) printed on graphic and photographic substrates in the form of a reel or single sheets, the substrates having an optical recognizing mark (M) between successive images, the device comprising:

• a movable cutting unit (7) having a cutting blade operated by a cutting-blade motor (9), the cutting blade defining a cutting line extending in a transverse direction relative to a feed path and having a cutting-line length, the movable cutting unit operatively coupled to at least one cutting-unit angular adjustment motor (5, 5′) to angularly adjust an orientation of the cutting unit (7) for adjusting an angular orientation of the cutting line;
• a pair of feed rollers (2) extending in a transverse direction relative to the feed path and driven by a feed-roller drive motor (3), the pair of feed rollers (2) having a nip length less than the cutting-line length for engaging a central portion of a width of the substrate and feeding the substrate along the feed path;
• a pair of optical sensors (4, 4′) between the pair of feed rollers (2) and the movable cutting unit (7), the pair of optical sensors (4, 4′) configured to detect one of the optical recognizing marks (M);
• two length differential measuring devices (6, 6′) configured to detect different feed lengths of the substrate (10) as the substrate passes the two length differential measuring devices (6, 6′);
• the pair of feed rollers (2) being positioned between the two length differential measuring devices (6, 6′);
• and
• a microprocessor (11) in communication with the pair of optical sensors (4, 4′), the two length differential measuring devices (6, 6′), and the at least one cutting-unit angular adjustment motor (5, 5′), and configured to control the orientation of the cutting unit (7) based on substrate entry-angle data from the pair of optical sensors (4, 4′) and based on substrate skid-angle data from the two length differential measuring devices (6, 6′).