Inkjet Head Channel Layout for Uniform Nozzle Pressure

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Solution Overview

Problem

Conventional inkjet recording apparatuses face challenges in maintaining ejection stability of nozzle sections due to pressure distribution imbalances and pressure loss variations, particularly when using high-viscosity inks, leading to issues like ink overflow and air bubble entrainment.

Innovation Solution

The inkjet head and apparatus feature a configuration where the pressure loss resistances of individual circulation channels are greater than those of individual supply channels, with uniform pressure loss resistances in circulation channels and non-uniform resistances in supply channels to ensure uniform pressures across nozzle sections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the cross-sectional area of individual circulation channels is made small to increase pressure loss resistance, then pressure escape and propagation can be suppressed, but manufacturing precision and uniformity become difficult to achieve

Engineering Contradiction:
Improveejection stabilityVSAvoidpressure loss resistance uniformity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent changes the pressure loss resistance parameter by making circulation channels longer rather than smaller in cross-section. This achieves high pressure loss resistance (suppressing pressure escape) while maintaining manufacturable dimensions and uniformity. The length parameter is adjusted to compensate for the larger cross-sectional area, preserving both reliability and manufacturing precision.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If high-viscosity ink is used to improve print quality, then ejection stability deteriorates due to large pressure differences in supply channels

Engineering Contradiction:
Improveprint qualityVSAvoidejection stability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies preliminary anti-action by pre-balancing the pressure distribution through asymmetric pressure loss resistance design before ink ejection occurs. The circulation channels are designed with higher pressure loss resistance than supply channels, which compensates for the pressure differences caused by high-viscosity ink flow, preventing ejection instability before it occurs.

Inventive Principle:
Principle #9Preliminary anti-action

3Device complexity

If pressure loss resistance of circulation channels is made equal to supply channels, then channel simplicity is maintained, but pressure distribution uniformity across nozzles deteriorates

Engineering Contradiction:
Improvechannel configurationVSAvoidpressure distribution uniformity
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by creating different pressure loss resistance characteristics in different parts of the fluid path. Specifically, the circulation channels are designed with higher pressure loss resistance than the supply channels, establishing a localized pressure gradient that ensures uniform pressure distribution across all nozzle sections while maintaining overall system simplicity.

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 configuration enhances the ejection stability of nozzle sections, preventing pressure escape and propagation, thereby ensuring reliable ink ejection.

Implementation Method 1

pressure loss resistances of the plurality of individual circulation channels having greater overall pressure loss resistance than the plurality of individual supply channels

Methodology Applied
Scientific EffectPressure loss resistance: Pressure Drop

Data Source

PatentEP4681922A1Inkjet head and inkjet recording device
Publication Date: 2026.01.21 KONICA MINOLTA INC
  • EP4681922A1 patent drawingFigure 1
  • EP4681922A1 patent drawingFigure 2
  • EP4681922A1 patent drawingFigure 3

AI summary

This inkjet head comprises a plurality of individual supply channels that individually supply ink from a common supply channel to a plurality of nozzle parts, and a plurality of individual circulation channels that individually discharge the ink from the plurality of nozzle parts to the common circulation channel, the individual pressure loss resistance of the plurality of individual circulation channels, for which the overall pressure loss resistance is greater than that of the plurality of individual supply channels, being made uniform, and the individual pressure loss resistance of the plurality of individual supply channels being made nonuniform so that the pressure of the plurality of nozzle parts is made uniform.