Staggered Print Head Die Overlap for Dot Placement Accuracy

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Solution Overview

Problem

Inkjet printers with page-wide array print heads face print quality defects due to spacing between print head dies, which affects dot placement accuracy and color mixing, especially in low-cost manufacturing processes where precise alignment is challenging.

Innovation Solution

The implementation of a printing system with staggered and overlapping print head dies, where electrical interconnects are spaced to allow closer die spacing, reducing the print zone width and enhancing dot placement accuracy, and using a method to determine optimal overlap and stagger distances based on manufacturing variations and media movement errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If print head dies are spaced apart to accommodate electrical interconnects, then ease of manufacture is improved, but printing quality deteriorates due to reduced dot placement accuracy and color mixing

Engineering Contradiction:
Improveease of manufactureVSAvoiddot placement accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent transitions from a linear arrangement of print head dies to a two-dimensional staggered grid pattern. This dimensional change allows electrical interconnects to route between non-adjacent dies while maintaining close spacing across the media width, resolving the conflict between manufacturing ease and dot placement accuracy

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The print head assembly is divided into multiple independent print head dies arranged in staggered rows. Each die can be manufactured and tested separately, then assembled into the final array. This segmentation enables closer effective spacing while simplifying manufacturing and reducing the impact of spacing issues on overall print quality

Inventive Principle:
Principle #1Segmentation

2Device complexity

If print head dies are spaced apart for electrical interconnect routing, then device complexity is reduced, but printing quality deteriorates due to wider print zone width

Engineering Contradiction:
Improvedevice complexityVSAvoidcolor mixing
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

By arranging dies in staggered rows rather than single file, the patent creates a two-dimensional layout that reduces the effective print zone width in the media width direction. This allows better color mixing and dot placement accuracy while keeping the electrical interconnect routing manageable

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

Multiple print head dies are combined in a staggered array configuration where adjacent dies in different rows overlap in their print zones. This merging of print zones from multiple dies ensures accurate color mixing and dot placement while the staggered arrangement keeps the overall device complexity manageable

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2864122B1Print head die
Publication Date: 2020.02.19 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP2864122B1 patent drawingFigure 1~2
  • EP2864122B1 patent drawingFigure 3
  • EP2864122B1 patent drawingFigure 4

AI summary

Various configurations of print head die are described. In an example, a first print head die has first print structures disposed along a major dimension thereof perpendicular to the media path, the first print structures including a leading print structure with respect to the media path. A second print head die independent of the first print head die has second print structures disposed along a major dimension thereof perpendicular to the media path, the second print head die being staggered with respect to the first print head die along the media path, the second print structures including a leading print structure with respect to the media path. A portion of the second print structures overlap a portion of the first print structures by an extent between a minimum value and a linear function of a separation between the respective leading print structures of the first and second print head dies.