Patent ID: 8449067
Filing Date: 2013-05-28
Classification: B41J

Abstract:
1. A method for operating an inkjet printing device with at least one inkjet printhead having a row of nozzles for directing ink onto a substrate being conveyed in a transport direction over a cylinder in an offset press, said method comprising arranging said at least one printhead transversely of said transport direction so that adjacent nozzles lie at different distances from the substrate, whereby the ink from adjacent nozzles has different nozzle to substrate travel times; generating a bitmap of an image to be printed on the substrate by each said printhead, each said bitmap comprising image data assigned to respective nozzles; adjusting each said bitmap in a pre-printing stage so that image data assigned to nozzles which are farther away from the substrate is shifted upstream in the printing direction relative to image data for nozzles which are closer to the substrate; and actuating the nozzles in each said row so that the different nozzle to substrate travel times for the nozzles of each row are compensated by the adjusted bitmap.