Dummy Pressure Chamber for Uniform Ink Ejection

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Solution Overview

Problem

In liquid ejecting apparatuses, such as ink jet type recording devices, achieving uniform ejection characteristics across all pressure chambers is challenging due to differences in pressure loss and rigidity of partition walls, especially with increased nozzle density and use of materials like single crystal silicon substrates.

Innovation Solution

Incorporating dummy pressure chambers with piezoelectric elements that receive a continuous drive potential, supporting adjacent partition walls and maintaining uniform deformation, thereby reducing pressure loss and ensuring consistent ejection characteristics across all pressure chambers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If nozzle density is increased and miniaturization is pursued, then productivity and resolution are improved, but pressure loss differences between end portion pressure chambers and inner pressure chambers become more significant, deteriorating ejection characteristic uniformity

Engineering Contradiction:

Improvenozzle densityVSAvoidejection characteristic uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

A dummy pressure chamber is introduced as an intermediary element between the end portion pressure chamber and the outer environment. This dummy chamber acts as a mediator that equalizes pressure loss characteristics by providing an additional pressure release path, thereby compensating for the structural differences between end portion and inner pressure chambers and achieving uniform ejection characteristics across all nozzles.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the pressure loss parameter by modifying the structure of the end portion pressure chamber system. By introducing the dummy pressure chamber with a specific opening configuration, the pressure loss parameter is adjusted to match that of inner pressure chambers, thereby achieving uniform ejection characteristics despite increased nozzle density.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If a dummy pressure chamber is added to equalize pressure loss, then ejection characteristic uniformity is improved, but device complexity increases

Engineering Contradiction:

Improveejection characteristic uniformityVSAvoidstructure complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The dummy pressure chamber structure is designed to serve multiple functions: it acts as a pressure equalization element, provides a structural support for the partition wall, and maintains uniform deformation characteristics across all pressure chambers. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity while achieving ejection characteristic uniformity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Strength

If partition wall rigidity is increased to maintain structural stability, then strength is improved, but pressure loss differences between pressure chambers become more significant, deteriorating ejection uniformity

Engineering Contradiction:

Improvepartition wall rigidityVSAvoidejection uniformity

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The invention applies local quality by providing enhanced structural support only at specific locations where needed. The dummy pressure chamber opening is positioned to provide localized support to the partition wall in the end portion pressure chamber, allowing that specific area to have higher effective rigidity while maintaining uniform pressure loss characteristics overall, thereby achieving both structural stability and ejection uniformity.

Inventive Principle:

Principle #3Local quality

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

This approach allows for uniform ejection characteristics across all pressure chambers, accommodating high nozzle density and miniaturization, and is suitable for substrates with relatively weak rigidity, enhancing image quality and operational efficiency.

Implementation Method 1

drives a piezoelectric element by applying a drive potential to the piezoelectric element and thus causing liquid to be ejected from a nozzle

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS9050792B2Liquid ejecting apparatus and method of controlling liquid ejecting apparatus

Publication Date: 2015.06.09 SEIKO EPSON CORP

AI summary

A pressure chamber array includes one or more dummy pressure chambers in which ejection of ink is not performed, the dummy pressure chamber includes a piezoelectric element, and a drive potential generator continues to apply a drive potential to the piezoelectric element corresponding to the dummy pressure chamber, while the ejection of the ink from a nozzle of at least a pressure chamber adjacent to the dummy pressure chamber is performed.