Compensation method for failed printing nozzles

US10449759B2 · kind B2 · utility

Assignee

• Heidelberger Druckmaschinen AG · DE

Inventors

• Ilias Trachanas · Plankstadt, DE
• Martin Mayer · Ladenburg, DE
• Peter Hachmann · Dossenheim, DE

Key dates

• Filing date: Aug 23, 2018
• Grant date: Oct 22, 2019
• Expiry date: Aug 23, 2038

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B41J2025/008
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

A method corrects for defective printing nozzles in an ink jet printing machine via a computer. The defective printing nozzles are compensated for after the screening process by neighboring printing nozzles applying an increased amount of ink. The method includes precalculating different compensation halftones for different area coverages by the computer, printing the compensation halftones embedded in area coverage halftone areas, evaluating the printed compensation halftones via the computer, and selecting and saving, for every area coverage level, the compensation halftone that best matches the coloration of the original halftone in the respective area coverage halftone area. A defective printing nozzle is detected during production printing by the computer. The local area coverage is determined along the detected defective printing nozzle by the computer. The compensation halftone that has been saved for the determined local area coverage is used to compensate for the defective printing nozzles via the computer.