Ink Jet Head Wiring Segmentation for Noise Reduction

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Solution Overview

Problem

The existing ink jet printer technologies face issues with complicated and thin common wiring on flexible substrates, leading to noise, degradation of ejection properties, and cumbersome wiring operations, due to the need for discrete and common wiring configurations that can result in voltage dropping and improper drive IC operations.

Innovation Solution

The design incorporates a configuration where the common wiring is eliminated on the flexible substrate, with a head substrate, flexible substrate, and relay substrate arrangement, where the common connection wiring is separate from the drive IC, and the reference potential wiring is independently connected to the relay substrate, reducing the complexity and thickness of wiring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the common wiring is disposed via the drive IC chip on the flexible substrate, then the wiring route is simplified, but noise is transmitted through the common wiring and improper operations of the drive IC may occur

Engineering Contradiction:
Improvewiring route complexityVSAvoiddrive IC operation stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the flexible substrate into multiple regions: a first flexible substrate region containing the drive IC chip and discrete wirings, and a second flexible substrate region containing the common wiring. This spatial segmentation prevents noise transmission from the common wiring to the drive IC chip, while maintaining simplified wiring routing. The segmentation resolves the contradiction by physically separating noise-sensitive and noise-generating components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the common wiring from the drive IC region by disposing it in a separate second flexible substrate region. This extraction removes the harmful noise transmission path from the drive IC chip area, while the common wiring still serves its function of providing reference potential to all elements. This resolves the contradiction by removing the harmful effect while preserving the beneficial simplified routing.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If the width of the common wiring is increased to reduce voltage dropping, then ejection properties improve, but the area of the drive IC increases

Engineering Contradiction:
Improveejection property stabilityVSAvoiddrive IC area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent moves the common wiring from the constrained drive IC area to a separate second flexible substrate region, effectively utilizing another spatial dimension. This allows the common wiring to have sufficient width for low resistance without occupying drive IC area. The dimensionality change resolves the contradiction by decoupling the wiring width requirement from the drive IC footprint.

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

3Device complexity

If the common wiring is disposed through a route different from the flexible substrate, then wiring complexity is reduced, but the wiring becomes long and complicated leading to noise and voltage dropping

Engineering Contradiction:
Improvewiring configuration simplicityVSAvoidsignal quality and voltage stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the flexible substrate into distinct regions for different wiring functions. The common wiring is confined to the second flexible substrate region, allowing it to be optimized for low resistance and noise immunity without interfering with the drive IC region. This segmentation enables the common wiring to maintain simplicity while achieving sufficient length and quality for reliable operation.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3528603B1Ink jet head and ink jet printer
Publication Date: 2020.10.21 TOSHIBA TEC KK
  • EP3528603B1 patent drawingFigure 1A~1B
  • EP3528603B1 patent drawingFigure 2A~2B
  • EP3528603B1 patent drawingFigure 3A~3E

AI summary

An ink jet head includes a head substrate, a flexible substrate, and a relay substrate. The head substrate includes ink jet elements and a common wiring that extends from an edge of the head substrate and electrically connects in common to the ink jet elements. The flexible substrate is coupled to the head substrate at a first edge and includes a drive circuit, a common connection wiring that extends between the first edge and a second edge opposite the first edge and is electrically connected to the common wiring, and a first reference potential wiring electrically connected to a reference voltage terminal of the drive circuit and disposed separately from the common connection wiring. The flexible substrate includes an output monitor wiring extending from an output terminal of the driver circuit to the second edge through a region between the common connection wiring and the first reference potential wiring.