Printhead Alignment Method Using Colorimetric Drop Analysis

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Solution Overview

Problem

Existing methods for aligning printheads in printing machines are limited by inaccuracies in drop ejection and require significant computational resources, with the number of printheads affecting overall processing time.

Innovation Solution

A method that uses a computer system to detect and analyze the colorimetric and spatial coordinates of printed drops, creating lists of points with similar coordinates, filtering and vectorizing groups, and associating vectors with printheads to correct alignment, minimizing computational resources and improving precision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If digital adjustment methods are used on point printing marks to align printheads, then alignment precision is improved, but computational resources and processing time increase significantly

Engineering Contradiction:
Improvealignment precisionVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent segments the image processing into distinct stages: detection of printing marks, extraction of spatial coordinates, grouping of points by colorimetric coordinates, and vectorization. This segmentation allows each stage to be optimized independently, reducing overall computational burden while maintaining precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by processing only the necessary points for alignment rather than the entire image. It identifies and processes only the printing marks that are relevant for alignment, filtering out extraneous data to reduce computational resources required.

Inventive Principle:
Principle #16Partial or excessive action

2Measurement precision

If digital adjustment methods are used on point printing marks to align printheads, then alignment precision is improved, but computational resource usage increases

Engineering Contradiction:
Improvealignment precisionVSAvoidcomputational resource usage
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent extracts only the essential information from the printed image - the spatial coordinates and colorimetric coordinates of printing marks. By taking out only the necessary data points for alignment and discarding redundant information, computational resource usage is minimized while maintaining alignment precision.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent performs partial processing by focusing computational efforts only on the printing marks that contribute to alignment, rather than processing the entire image. This selective approach reduces energy consumption and computational resource usage.

Inventive Principle:
Principle #16Partial or excessive action

3Device complexity

If traditional alignment methods are used that rely on drop ejection positions, then device complexity is reduced, but manufacturing precision deteriorates due to ejection inaccuracies

Engineering Contradiction:
Improvealignment system complexityVSAvoidprinthead alignment precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent creates a digital copy of the printed pattern by detecting and recording the positions of printing marks on the substrate. This digital model serves as a reference for alignment calculations, replacing the need for complex physical measurement systems while achieving high precision through image processing.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces mechanical alignment methods based on drop ejection positions with an optical-digital system. Instead of relying on the physical positions where drops are ejected, the system uses image detection and digital processing to determine and correct alignment, eliminating the impact of ejection inaccuracies.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP2844490B1Method for checking the alignment of print heads and associated alignment method
Publication Date: 2016.10.05 MGI FRANCE
  • EP2844490B1 patent drawingFigure 1
  • EP2844490B1 patent drawingFigure 2
  • EP2844490B1 patent drawingFigure 3

AI summary

ABSTRACT INVENTOR: Edmond Abergel Romain Poncet Thierry Brionne APPLICANT: MGI The aim of the present invention is to propose a method for assessing and correcting the alignment of print heads carried out using at least one linear adjustment algorithm, allowing greater accuracy in the use of same by eliminating inaccuracies linked to the ejection of drops from the print heads, while limiting the use of the resources of the IT system on which the method is used. Moreover, the number of print heads of which the alignment needs to be assessed and optionally corrected has very little influence on the overall processing time required by said method.