APPARATUS FOR INVALIDATING PRINTS PRINTED ON PRINTING CARRIERS

摘要

The apparatus for invalidating the prints printed on moving printing carriers (3) comprises a linear motor (1) and a detector (5). The linear motor (1) comprises a moving part (1a) to which a marker (2) is fixed. The detector (5) is arranged after the linear motor (1) in the direction of advance of the printing carrier. It checks whether the marking of the defective print has been accomplished in a manner so as to be recognized during the following treatments of the printing carrier. When a print has been recognized as being defective by a printing quality control system, a start-of-marking signal is sent to the linear motor (1) which thereafter presses its moving part (1a), fitted with the marker (2), against the place of this print on the printing carrier (3). An end-of-marking signal is then sent to the motor (1) in order to withdraw the marker (2) from the printing carrier.