Rotary polychrome printing machine register monitoring system uses two linear sets of register marks picked up by reading cell

摘要

The system consists of a number of stations each printing one color and a separate register mark (10, 20, 30, 40, 50) picked up by a reading cell, a lengthwise space detector for the marks and a corrector to control the paper strip. It has a second set of register marks (12, 22, 32, 42, 52) which are read by the cell (100) after the first set and are printed closer together, i.e. about 2 mm apart compared with 20 mm apart for the first set. The marks in the first set are triangular in shape and about 8 mm wide, while those in the second set are in the form of bars about 1 mm thick.