Printer Nozzle Overlap Masking for Image Quality

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Solution Overview

Problem

Page-wide array printers face challenges in maintaining image quality due to mechanical tolerances and ink interactions between overlapping nozzle arrays, leading to defects in one-pass print modes, particularly with high contrast colors like yellow and black.

Innovation Solution

The implementation of weaving masks that control the sequence and position of nozzle firing in overlap zones, ensuring consistent ink interactions by always firing specific color nozzles last or first, and using strategies like random taper and checkerboard patterns to distribute the print pattern between overlapping dies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If overlapping nozzle arrays are used to compensate for mechanical tolerances, then printing coverage and reliability are improved, but image quality deteriorates due to inconsistent ink interactions in overlap zones

Engineering Contradiction:
Improveprinting coverageVSAvoidimage quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies different quality treatments to different zones: in overlap zones, it enforces fixed ink interaction sequences to ensure consistent tone, while in non-overlap zones, it allows flexible nozzle selection. This local differentiation resolves the contradiction by maintaining reliability through overlap coverage while preserving image quality through zone-specific control strategies

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system dynamically adjusts the ink interaction sequence based on location: in overlap zones, it fixes the sequence to maintain consistent tone, while in non-overlap zones, it allows dynamic optimization for other quality metrics. This dynamic adaptation enables the system to maintain both reliability and image quality across different print zones

Inventive Principle:
Principle #15Dynamics

2Stability of the object's composition

If fixed hierarchy of ink application is used in overlap regions, then tone consistency is improved, but printing flexibility and adaptability deteriorate

Engineering Contradiction:
Improvetone consistencyVSAvoidprinting flexibility
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent implements local quality by applying fixed ink application hierarchies specifically in overlap zones to ensure tone consistency, while maintaining flexible nozzle selection in non-overlap zones. This localized approach preserves printing flexibility overall while ensuring tone consistency where it matters most

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The print zone is segmented into overlap zones and non-overlap zones, with different control strategies applied to each. This segmentation allows the system to enforce fixed hierarchies only where needed for tone consistency, preserving flexibility in other areas

Inventive Principle:
Principle #1Segmentation

3Productivity

If page-wide array printer is used for high-speed printing, then productivity is improved, but image quality control becomes more difficult due to one-pass printing

Engineering Contradiction:
Improveprinting speedVSAvoidimage quality control
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent performs preliminary actions by pre-determining the ink interaction sequences and nozzle selection strategies before printing. This allows the high-speed one-pass printer to maintain image quality control through pre-planned, optimized printing paths that account for overlap zone challenges

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system incorporates feedback mechanisms to monitor and adjust ink application in real-time during the one-pass printing process, enabling image quality control despite the high-speed continuous printing operation

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3238138B1Printer and method of controlling same
Publication Date: 2021.09.08 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3238138B1 patent drawingFigure 1
  • EP3238138B1 patent drawingFigure 2
  • EP3238138B1 patent drawingFigure 3

AI summary

A method of controlling a printer to print a pattern using a number of print head dies, each print head die including a number of nozzle trenches wherein each one of the number of nozzle trenches is associated with a different color, wherein the nozzles of neighboring dies overlap in respective overlap zones, the method comprising applying masks to the nozzles of neighboring dies in the respective overlap zones to distribute, in the overlap zones, the pattern to be printed between the nozzles of the respective neighboring dies, wherein the masks, in the overlap zones, retain the order in which the nozzles of selected nozzle trenches associated with a selected one of the colors are fired.