Liquid Ejection Head Channel Segmentation for Pressure Wave Control

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Solution Overview

Problem

Conventional liquid ejection heads face challenges in efficiently supplying and recovering ink, leading to issues such as liquid pooling and pressure wave propagation, which affect printing quality and efficiency.

Innovation Solution

The liquid ejection head incorporates a unique configuration of individual channels and common channels, including first, second, and third individual channels connected to pressurizing chambers, which are arranged to attenuate pressure waves and prevent liquid pooling, using a piezoelectric actuator to control ink ejection and recovery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a common channel is used for both supplying and recovering liquid, then the device complexity is reduced, but liquid pooling and pressure wave propagation occur affecting printing quality

Engineering Contradiction:
Improvechannel configurationVSAvoidprinting quality
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The common channel is segmented into separate supply channel and recovery channel portions, allowing independent optimization of liquid flow paths. This prevents liquid pooling and pressure wave propagation while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The harmful pressure wave propagation and liquid pooling effects are extracted and directed into the recovery channel, separating the useful liquid supply function from the harmful effects. This allows the supply channel to maintain stable pressure for high-quality printing.

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If individual channels are arranged to improve liquid supply efficiency, then productivity increases, but pressure waves propagate affecting ejection precision

Engineering Contradiction:
Improveink supply efficiencyVSAvoidejection precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The recovery channel acts as an intermediary that absorbs and dissipates pressure waves generated during high-speed ink supply. This allows efficient liquid delivery to multiple ejection units while preventing pressure wave interference with ejection precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The channel configuration is designed with symmetric individual channels connecting to the common channel, creating balanced liquid flow paths that reduce pressure wave propagation while maintaining high supply efficiency for multiple ejection units.

Inventive Principle:
Principle #26Copying

3Reliability

If liquid circulation is implemented to prevent clogging, then reliability improves, but fluid crosstalk between channels increases

Engineering Contradiction:
Improveclogging preventionVSAvoidfluid crosstalk
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The circulation system is segmented into individual channel circulation paths that are isolated from each other through the channel structure. This allows liquid circulation to prevent clogging in each channel while preventing fluid crosstalk between adjacent channels through proper channel wall 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 enhances printing quality by reducing liquid pooling and pressure wave propagation, improving the precision and efficiency of ink ejection, resulting in improved image quality and reduced fluid crosstalk.

Implementation Method 1

a pressurizing element which is provided on the liquid chamber, the pressurizing element configured to pressurize liquid in the liquid chamber

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP3357694B1Liquid ejection head and recording device
Publication Date: 2020.03.25 KYOCERA CORP
  • EP3357694B1 patent drawingFigure 1A~1B
  • EP3357694B1 patent drawingFigure 2
  • EP3357694B1 patent drawingFigure 3A~3B

AI summary

In a liquid ejection head, an ejection unit of a channel member includes an ejection hole, a pressurizing chamber connected to the ejection hole, a first channel and a second channel each connecting the pressurizing chamber and a first common channel, and a third channel connecting the pressurizing chamber and a second common channel. The first common channel, in the channel direction, includes a plurality of first portions, and a plurality of second portions each located between each two of the plurality of first portions and having smaller cross-sectional areas than those of the first portions in front and back of the same. In each of the plurality of ejection units, the first channel and the second channel are individually connected to two positions in the first common channel which sandwich at least one of the second portions between them.