Method for detecting and compensating for defective printing nozzles in an inkjet printing machine using a threshold calculation based on weighting factors

A method for detecting and compensating for defective printing nozzles in an inkjet printing machine with a computer, the method comprising the following steps:

• periodically printing at least one multi-row printing nozzle test chart formed of a specified number of horizontal rows of equidistant vertical lines disposed underneath one another for detection and including only printing nozzles of a print head of the inkjet printing machine contributing to the printing nozzle test chart in every row corresponding to the specified number of horizontal rows and printing at least one area coverage element geometrically associated with the at least one multi-row printing nozzle test chart;
• using at least one image sensor to record and using the computer to evaluate the at least one area coverage element and the printing nozzle test chart;
• using the computer to identify print defects by evaluating the recorded area coverage element and to allocate the print defects to defective printing nozzles;
• using the computer to evaluate the multi-row printing nozzle test chart based on thresholds to detect defective printing nozzles;
• and
• using the computer to carry out a comparison of the detected defective printing nozzles from the recorded area coverage element and from the printing nozzle test chart to identify detected defective printing nozzles causing defects in only one of the at least one area coverage element or the printing nozzle test chart and to calculate the thresholds to minimize an amount of the detected defective printing nozzles based on data from the comparison to compensate for the detected defective printing nozzles.