Liquid Ejecting Head With Overlapping Pressure Chambers

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Solution Overview

Problem

Ink jet recording heads face challenges in minimizing size while efficiently disposing pressure chambers and individual communication flow paths, particularly due to air bubbles that absorb pressure changes and hinder ink droplet discharge.

Innovation Solution

The design incorporates first and second common liquid chambers with individual flow paths that couple these chambers, featuring pressure chambers with energy generation elements, where the pressure chambers are arranged in rows shifted relative to each other, and individual communication flow paths that overlap adjacent pressure chambers, optimizing the arrangement to prevent air bubble interference and ensure efficient ink discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of stationary object

If pressure chambers are arranged in a conventional non-overlapping manner, then manufacturing is simpler, but the recording head size increases

Engineering Contradiction:

Improverecording head sizeVSAvoidflow path configuration complexity

Core Design Contradiction:

Volume of stationary objectVSDevice complexity

Solution Approach 1:

The patent applies dimensional change by arranging pressure chambers in overlapping rows when viewed in the ejection direction (third axis direction), transitioning from a conventional planar arrangement to a three-dimensional overlapping configuration. This allows the first and second pressure chamber rows to share the same footprint area while maintaining functional independence, thereby reducing the recording head size without excessive complexity increase

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent implements nesting by having individual communication flow paths pass through regions between adjacent pressure chambers of opposite rows. The flow paths are positioned to overlap with inter-chamber regions rather than occupying separate space, creating a nested arrangement where communication channels are embedded within the pressure chamber array structure

Inventive Principle:

Principle #7Nested doll (Nesting)

2Stability of the object's composition

If individual communication flow paths are lengthened to connect non-adjacent pressure chambers, then pressure distribution improves, but ink flow resistance increases

Engineering Contradiction:

Improvepressure distribution uniformityVSAvoidink flow resistance

Core Design Contradiction:

Stability of the object's compositionVSLoss of energy

Solution Approach 1:

The patent applies local quality by connecting each pressure chamber to adjacent pressure chambers of opposite rows rather than creating uniform long-distance connections. Each individual communication flow path is localized to connect nearby chambers, providing pressure distribution through short, efficient pathways that minimize resistance while maintaining composition stability

Inventive Principle:

Principle #3Local quality

3Volume of stationary object

If pressure chambers are arranged in overlapping rows, then recording head size is reduced, but manufacturing precision requirements increase

Engineering Contradiction:

Improverecording head sizeVSAvoidflow path alignment precision

Core Design Contradiction:

Volume of stationary objectVSManufacturing precision

Solution Approach 1:

The patent applies segmentation by dividing the pressure chamber array into distinct first and second rows that are offset from each other. This segmentation allows each row to be manufactured and positioned independently, with the overlapping arrangement providing natural alignment references that reduce the overall precision requirements compared to a fully integrated non-overlapping design

Inventive Principle:

Principle #1Segmentation

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 configuration effectively suppresses the increase in size of the recording head, stabilizes ink droplet discharge, and reduces variations in discharge characteristics by efficiently managing pressure changes across the nozzles.

Implementation Method 1

an energy generation element such as a piezoelectric actuator causing a pressure change of ink in the pressure chamber

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

ink is caused to flow from the first common liquid chamber to the second common liquid chamber through the individual flow paths

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentUS11766862B2Liquid ejecting head and liquid ejecting system

Publication Date: 2023.09.26 SEIKO EPSON CORP

AI summary

First and second individual flow paths coupling a first common liquid chamber to a second common liquid chamber are arranged side by side, and each individual flow path is provided with first and second pressure chambers. At least a part of the first individual flow path is provided in a space overlapping a region between the adjacent second pressure chambers when viewed in a Z axis direction, the space not overlapping the second pressure chamber when viewed in a Y axis direction.