Abstract: Cleaning of contamination in a printer, especially contamination by the use of a fixing aid, in which the contamination is determined by evaluating the register of a print of the printing machine. In the case that the register error is larger than a given amount, a cleaning run is performed. A control device is provided for evaluation of the register for determining contamination of the printer, especially by a fixing aid.

Abstract: A method for correction of the calibration of the register mark accurately and/or register accurate printing process of an electrophotographic printing unit, preferably of a color-printing unit. Large surface toner fields are placed on a conveyor belt for the substrate to be printed, particularly in the larger spaces between the substrate sheets to be printed. The influence of a toner field placed on a conveyor belt for print substrate sheets on the register mark and/or registration of the printing process is identified, and such influence is expressed in the form of at least one correction value or parameter suitable for the correction of the calibration.

Abstract: Ensuring proper compass and register positioning during printing. Marks are imprinted on a carrying element and at least one sensor is present to detect the marks on the carrying element and a second sensor detects a seam on the carrying element. A control mechanism receives mark values from the first sensor and seam values from the second sensor, and discarding mark values when the seam is detected.

Abstract: Avoiding eccentricity for a shaft, with a balance error, on which a hollow cylinder is applied, the hollow cylinder serving to compensate for the balance error of the shaft. A first mark on the hollow cylinder has a location on the hollow cylinder with a certain thickness of the hollow cylinder, and a second mark on the surface of the shaft has a location on the shaft with a certain radius with respect to the axial center of gravity of the shaft are aligned.

Abstract: A method for correction of the calibration of the register mark accurate and/or register accurate printing process of an electrophotographic printing unit, preferably of a color-printing unit. Large surface toner fields are placed on a conveyor belt for the substrate to be printed, particularly in the larger spaces between the substrate sheets to be printed. The influence of a toner field placed on a conveyor belt for print substrate sheets on the register mark and/or registration of the printing process is identified, and such influence is expressed in the form of at least one correction value or parameter suitable for the correction of the calibration.

Abstract: Ensuring proper compass and register positioning during printing. Marks are imprinted on a carrying element and at least one sensor is present to detect the marks on the carrying element and a second sensor detects a seam on the carrying element. A control mechanism receives mark values from said first sensor seam values from said second sensor, and discarding mark values when said seam is detected.

Abstract: 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.

Abstract: A process and printing machine for determining registration errors and correcting therefore. At least one first registration mark is applied onto a conveyor belt for transporting a sheet, and at least one second registration mark is applied onto the sheet adjacent to the first registration mark. The first registration mark and the second registration mark are detected, the distance between the first registration mark and the second registration mark is calculated, and the difference between the calculated distance and a distance without different speeds of the conveyor belt and the sheet (a target value) is calculated.

Abstract: A process and printing machine for determining registration errors and correcting therefore. At least one first registration mark is applied onto a conveyor belt for transporting a sheet, and at least one second registration mark is applied onto the sheet adjacent to the first registration mark. The first registration mark and the second registration mark are detected, the distance between the first registration mark and the second registration mark is calculated, and the difference between the calculated distance and a distance without different speeds of the conveyor belt and the sheet (a target value) is calculated.

Abstract: 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.