DUPLEX PRINTING

摘要

According to one example, there is provided a method of duplex printing. The method comprises printing recto pages and associated recto checkmarks on a first side of a web and printing verso pages and associated verso checkmarks on a second side of a web, the length of each successively printed recto and verso checkmark varying in accordance with a respective recto and verso checkmark length sequence, determining the length of successive printed verso and recto checkmarks and determining their sequence position in the appropriate checkmark length sequence, and determining whether a print error has occurred based on the determined recto and verso checkmark sequence positions.

主权项

1. A duplex printing system, comprising:
first and second print engines to respectively print on a first and second side of a web; a controller to:
control the first print engine to print recto pages and associated recto checkmarks;control the second print engine to print verso pages and associated verso checkmarks; andmodify the length of successive printed recto and verso checkmarks in accordance with a respective recto and verso checkmark length sequence; a recto checkmark sequence calculator to determine a sequence position in the recto checkmark length sequence of a printed recto checkmark; a verso checkmark sequence calculator to determine a sequence position in the verso checkmark length sequence of a printed verso checkmark; and a checkmark sequence verifier to determine print errors based on the determined recto and verso checkmark sequence positions.