Abstract: A method for inkjet printing an image onto a curved region of an object surface includes applying a screen of ink drops to the region to create print dots, calculating the screen using a computer and generating and applying ink drops to the region using a print head having nozzles on a nozzle surface. The steps include a) providing data representing the print image, b) providing or calculating data representing the region, c) providing or calculating path data on paths for the print head or object, d) calculating application locations of ink drops using data from steps b) and c), e) calculating data based on tiling the region using data from step d), f) calibrating tone values using data from step e), g) screening the print image using data from step f), and h) printing the screened image onto the region. A device implementing the method is also provided.

Abstract: A method for inkjet printing an image onto a curved region of an object surface includes applying a screen of ink drops to the region to create print dots, calculating the screen using a computer and generating and applying ink drops to the region using a print head having nozzles on a nozzle surface. The steps include a) providing data representing the print image, b) providing or calculating data representing the region, c) providing or calculating path data on paths for the print head or object, d) calculating application locations of ink drops using data from steps b) and c), e) calculating data based on tiling the region using data from step d), f) calibrating tone values using data from step e), g) screening the print image using data from step f), and h) printing the screened image onto the region. A device implementing the method is also provided.

Abstract: A method for cyclically conveying sheets through a printing-technological machine adjusts a sheet position with high accuracy. The sheets following one another are in each case held at the front edge in grippers of a gripper system during the conveyance, and wherein the sheet position is adjusted in that a pneumatic apparatus is actuated by a control device which processes signals from at least one fixed-location sensor for the sheet position, as at least one sheet runs past, a large number of measured position values of the sheet are determined successively by using at least one sensor, from the measured position values a characteristic value for the sheet position being determined in the control device, the characteristic value as actual value being compared with a setpoint, and the pneumatic apparatus being set for a following sheet as a function of the comparison in each case between the actual and intended value of the preceding sheet.

Abstract: A method for conveying a sheet includes guiding an electrically charged sheet pneumatically along a desired path, continuously detecting a charge distribution on the sheet, and reducing a positional deviation of the sheet from the desired path by actuating at least one actuating element influencing the position in dependence on the charge distribution. An apparatus for conveying a sheet includes a control device for the position of the sheet and a sensor connected to the control device for detecting an electric field present on the sheet. The method and apparatus permit the sheet to be guided with small deviations from the desired path.