The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 04, 2020
Filed:
Mar. 21, 2019
Heidelberger Druckmaschinen Ag, Heidelberg, DE;
Steffen Neeb, Bensheim, DE;
Nicklas Raymond Norrick, Heddesheim, DE;
Andreas Henn, Neckargemuend, DE;
Andreas Fehlner, Mannheim, DE;
Thomas Wolf, Heidelberg, DE;
Heidelberger Druckmaschinen AG, Heidelberg, DE;
Abstract
A method for detecting and compensating defective printing nozzles in an inkjet printing machine includes periodically printing at least one printing nozzle test chart having horizontal rows of equidistant vertical lines underneath one another, with only nozzles contributing to the test chart in every row corresponding to horizontal rows, and printing an area coverage element geometrically associated with the test chart. Both elements are recorded by an image sensor and evaluated by a computer. The computer identifies print defects by evaluating the area coverage element and allocates the defects to defective nozzles. The computer evaluates the test chart based on thresholds to detect defective nozzles and compensate detected defective nozzles. The computer compares the detected defective nozzles from the area coverage element and the test chart to identify detected defective nozzles causing defects in only one element and calculates the thresholds based thereon to minimize the detected defective nozzles.