Method for assessing the condition and improving the printing quality of printing nozzles in printheads of an inkjet printing machine and improved printing nozzle test chart

US11198288B2 · kind B2 · utility

Assignee

• Heidelberger Druckmaschinen AG · DE

Inventors

• Andreas Fehlner · Mannheim, DE
• Hans Koehler · Graz, AT

Key dates

• Filing date: Jan 15, 2020
• Grant date: Dec 14, 2021
• Expiry date: Jan 15, 2040

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 for assessing the condition and improving the printing quality of printing nozzles in printheads of an inkjet printing machine includes printing a nozzle test chart formed of a specific number of horizontal rows of equidistant vertical lines printed periodically underneath one another, with only every nth printing nozzle contributing to the test chart in every row of the test chart and n corresponding to a different number between one and the specific number of horizontal rows, recording and digitizing the test chart and analyzing the test chart regarding the condition of the contributing nozzles by using a computer. The nozzles printing horizontal lines between the horizontal rows complementing the equidistant vertical lines to form quadrangular objects used by the computer to analyze the condition of the contributing nozzles. Measures are taken to improve the printing quality of the nozzles depending on the condition of the contributing nozzles.