Sheet sensor for use with a drum

摘要

A sheet sensor arrangement for a sheet printing machine and particularly for a turning device of a sheet printing machine, which comprises at least one hollow cylindrical drum (3; 4), which has a gripper system to transport and/or temporarily store individual sheets (5). A sensor arrangement which is not very susceptible to contamination and has a mechanically simple structure is comprised of the fact that the cylindrical wall of the drum (3; 4) has at least one opening which allows light to pass through, and that a sheet sensor is formed by a light barrier (9, 10, 11), which has a light beam which, in at least one angle position of the drum, is directed from the inside at the opening which allows light to pass through. In addition, a corresponding process for optical monitoring of sheets in a sheet printing machine is indicated.