Method and control device for determining a register error

1. Method to determine a register error in a printing machine, whereby at least one register mark ( 2 , 2 ′, 2 ″, 2 ″′) is printed and at least one sensor ( 15 , 15 ′) records the at least one register mark ( 2 , 2 ′, 2 ″, 2 ″′), comprising the steps of: sensing and recording the sheet edge of the sheet ( 3 , 3 ′, 3 ″, 3 ″′) by the sensor ( 15 , 15 ′), determining register error from sensor data and target data, the register error being determined for various types of print substrates and stored in an allocation table of a control device in the printing machine.

2. Method to determine a register error according to claim 1 , wherein the register mark ( 2 , 2 ′, 2 ″, 2 ″′) is printed on a conveyor ( 11 ) to advance a sheet ( 3 , 3 ′, 3 ″, 3 ″′).

3. Method to determine a register error according to claim 1 , wherein the recording of the register mark ( 2 , 2 ′, 2 ″, 2 ″′) and the sheet edge of the sheet ( 3 , 3 ′, 3 ″, 3 ″′) is carried out during the printing process.

4. Method to determine a register error according to claim 1 , wherein a register error is recorded in the conveying direction of the sheet ( 3 , 3 ′, 3 ″, 3 ″′).

5. Method to determine a register error according to claim 1 , wherein a register error perpendicular to the conveying direction of sheet ( 3 , 3 ′, 3 ″, 3 ″′) is detected, whereby the sensor ( 15 , 15 ′) records at least one side edge of the sheet ( 3 , 3 ′, 3 ″, 3 ″′).

6. Method to determine a register error according to claim 1 , wherein at least two register marks ( 2 , 2 ′, 2 ″, 2 ″′) are applied at a distance at right angles to the conveying direction; the register error is detected in the conveying direction of the sheet, and an angle error of the sheet ( 3 , 3 ′, 3 ″, 3 ″′) is determined from the sensor data.

7. Method to determine a register error according to claim 1 , wherein a number of register errors are statistically averaged.