Process and device for determining registration errors

摘要

Determining and correcting registration errors, which are caused by the rotational speed of a print cylinder changing because of a sheet passing between the print cylinder and a sheet transport conveyor belt. At least one first registration mark is applied onto the conveyor belt prior to a sheet being transported thereby, and at least one second registration mark is applied onto the conveyor belt after the transported sheet. By the detection of the first registration mark and the second registration mark, a calculation of a timing number between the detection of the first registration mark and the second registration mark can be made. The calculated timing number is compared to a target value to determine any error due to change in angular velocity of the print cylinder due to engagement with the sheet.