Metallic Reinforcement for Liquid Ejection Communication Opening

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Solution Overview

Problem

The circumferentially facing portion of the laminated body around the communication opening in liquid ejection apparatuses is susceptible to damage due to external forces and pressure from ink flow, as it is not supported by the channeled substrate and is subjected to adhesive shrinkage and vibration from piezoelectric driving.

Innovation Solution

Incorporating a metallic layer around the communication opening to reinforce the circumferentially facing portion, which is electrically connected to the common electrode and extends from the vibration plate to the annular wall portion, providing structural support and preventing damage from ink pressure and vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the circumferentially facing portion is made thin to reduce overall device thickness, then the device becomes more compact, but the portion becomes more susceptible to damage from external forces and ink pressure

Engineering Contradiction:
Improvedevice thicknessVSAvoidsusceptibility to damage
Core Design Contradiction:
Volume of moving objectVSStrength

Solution Approach 1:

The circumferentially facing portion is constructed as a composite structure combining a thin laminated body with an integrated metallic reinforcement layer. The metallic layer (e.g., aluminum, stainless steel) is formed on the circumferential surface to provide high strength and damage resistance, while the thin laminated body maintains compactness. This composite approach allows the device to achieve both reduced thickness and enhanced durability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The metallic reinforcement layer is applied locally only to the circumferentially facing portion where damage susceptibility is highest, rather than reinforcing the entire device. This localized reinforcement strategy provides targeted strength enhancement at the critical communication opening area while maintaining overall device compactness and minimizing additional material usage.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If adhesive is applied to bond the reservoir formation substrate to the laminated body, then bonding is achieved, but adhesive shrinkage applies additional force to the circumferentially facing portion causing potential damage

Engineering Contradiction:
Improvebonding capabilityVSAvoidstructural integrity
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The metallic reinforcement layer is formed on the circumferentially facing portion before the adhesive bonding process. This pre-reinforcement acts as a cushioning structure that absorbs and distributes the shrinkage forces generated during adhesive curing, preventing these forces from damaging the thin laminated body structure.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The metallic layer bonded to the laminated body creates a composite structure with superior mechanical properties. This composite construction provides both the bonding interface for the reservoir formation substrate and the structural reinforcement needed to withstand adhesive shrinkage forces during the manufacturing process.

Inventive Principle:
Principle #40Composite materials

3Productivity

If the piezoelectric elements are driven to vibrate for ink ejection, then ink ejection function is achieved, but vibrations are applied to the circumferentially facing portion causing potential damage

Engineering Contradiction:
Improveink ejection functionVSAvoidvibration resistance
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The metallic reinforcement layer integrated with the laminated body creates a composite structure with high vibration resistance. This composite construction dampens and absorbs the vibrations generated during piezoelectric element operation, protecting the thin circumferentially facing portion from vibration-induced damage while maintaining full ink ejection functionality.

Inventive Principle:
Principle #40Composite materials

4Strength

If the circumferentially facing portion is reinforced with a metallic layer, then damage susceptibility is reduced, but device complexity increases

Engineering Contradiction:
Improvedamage resistanceVSAvoidstructural complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The metallic reinforcement layer is integrated directly into the circumferentially facing portion structure, merging the reinforcement function with the existing laminated body rather than adding it as a separate component. This integration approach enhances damage resistance while minimizing increases in device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The metallic layer is formed using thin-film deposition techniques that maintain minimal thickness, changing the material parameter rather than adding substantial structural complexity. This allows the circumferentially facing portion to achieve enhanced strength through material property changes rather than complex structural additions.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The metallic layer effectively reduces the susceptibility of the circumferentially facing portion to damage, maintaining the integrity of the liquid ejection apparatus by distributing external forces and preventing ink leakage, while ensuring reliable ink supply to the pressure chambers.

Implementation Method 1

The metallic layer effectively reduces the susceptibility of the circumferentially facing portion to damage, maintaining the integrity of the liquid ejection apparatus by distributing external forces and preventing ink leakage

Methodology Applied
Scientific EffectStress distribution:

Implementation Method 2

The laminated body includes a vibration plate covering the pressure chambers and a plurality of piezoelectric elements corresponding to the pressure chambers

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP2923839B1Liquid ejection apparatus and a method for producing liquid ejection apparatus
Publication Date: 2017.04.19 BROTHER KOGYO KK
  • EP2923839B1 patent drawingFigure 1
  • EP2923839B1 patent drawingFigure 2
  • EP2923839B1 patent drawingFigure 3

AI summary

A liquid ejection apparatus comprising: a nozzle; a first channeled structure defining a first liquid channel, the first liquid channel communicating with the nozzle; a second liquid channel; a communication opening connecting the first liquid channel and the second liquid channel; a laminated body including a piezoelectric element and a metal layer, the laminated body having a first portion supported by the first channeled structure and a second portion extending over the first liquid channel and not supported by the first channeled structure, the communication opening extending through the second portion of the laminated body such that the second portion surrounds the communication opening; wherein the second portion of the laminated body includes the metal layer surrounding the communication opening.