Automated image sensor calibration

Abstract

A method calibrates image sensors and adjusts print heads in an inkjet printing machine via a computer. The method includes printing a test print chart, recording the printed test print chart via an image sensor to create a digital image, determining a coordinate transformation between the coordinates on the test print chart and the coordinates of the image sensor and the print heads, implementing a computer-assisted evaluation process of the digital image to determine the coordinates on the test print chart, deriving correction values for print head adjustment and camera calibration from results of the coordinate transformation and/or the comparison thereof with the determined measured values, and implementing the print head adjustment and the camera calibration by the computer. The test print chart has filled circular discs. The filled circular discs have a minimum diameter that is selected for them to function even if defective printing nozzles occur.