Liquid Discharge Head Dual Common Flow Paths

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Solution Overview

Problem

Existing liquid discharge heads face challenges in achieving uniform and efficient liquid distribution across a wide printing area without gaps, leading to potential issues with sedimentation and sticking of ink, especially when dealing with varying viscosities and flow rates.

Innovation Solution

The liquid discharge head employs a configuration with overlapping first and second common flow paths, optimized discharge hole arrangements, and a piezoelectric actuator substrate to ensure consistent liquid pressure and flow distribution, minimizing sedimentation and sticking by maintaining zero flow at the center, thus stabilizing liquid distribution across the discharge area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single common flow path is used to supply liquid to multiple discharge holes, then the device complexity is reduced, but the liquid distribution uniformity deteriorates leading to sedimentation and sticking

Engineering Contradiction:
Improveflow path structureVSAvoidliquid distribution uniformity
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The common flow path is divided into multiple separate flow paths (first common flow path and second common flow path) that supply liquid to different groups of discharge holes. This segmentation ensures that each flow path can be optimized independently for its specific discharge hole group, preventing sedimentation and sticking while maintaining manageable device complexity through modular architecture.

Inventive Principle:
Principle #1Segmentation

2Productivity

If discharge holes are arranged to cover a wide printing area, then the productivity is improved, but the liquid distribution uniformity deteriorates causing gaps in printing

Engineering Contradiction:
Improveprinting area coverageVSAvoidliquid distribution uniformity
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

Different flow paths are designed with different numbers of discharge holes according to the required printing area. The first common flow path supplies a first number of discharge holes while the second common flow path supplies a second number of discharge holes, allowing each region to be optimized for its specific requirements while collectively achieving wide area coverage with uniform liquid distribution.

Inventive Principle:
Principle #3Local quality

3Productivity

If the flow path impedance is reduced to improve liquid flow, then the productivity is improved, but the liquid pressure control deteriorates leading to inconsistent discharge

Engineering Contradiction:
Improveliquid flow rateVSAvoidliquid pressure consistency
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The liquid discharge system uses piezoelectric actuators that dynamically adjust the discharge timing and pressure for each discharge hole based on real-time requirements. This dynamic control allows the system to maintain consistent liquid pressure and discharge characteristics even with reduced flow path impedance, enabling high productivity without sacrificing precision.

Inventive Principle:
Principle #15Dynamics

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 sedimentation and sticking, maintaining consistent liquid distribution, and allowing for efficient printing across a wide area with reduced viscosity-related issues, thereby improving the overall printing resolution and speed.

Implementation Method 1

a piezoelectric actuator substrate 40 on which displacement elements 50 functioning as pressurizing units are built

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP3590717B1Liquid discharge head, recording device using same, and recording method
Publication Date: 2022.07.27 KYOCERA CORP
  • EP3590717B1 patent drawingFigure 1A~1B
  • EP3590717B1 patent drawingFigure 2A~2B
  • EP3590717B1 patent drawingFigure 3

AI summary

A liquid discharge head 2 of the present disclosure includes: a flow path member 4 having a plurality of pressurizing chambers 10 connected to respective discharge holes 8, a first common flow path 20 commonly connected to the plurality of pressurizing chambers 10, and a second common flow path 22 commonly connected to the plurality of pressurizing chambers 10; and a plurality of pressurizing units 50 that pressurizes the respective pressurizing chambers 10, in which the first common flow path 20 extends in a first direction and is open to an outside of the flow path member 4 at both end portions, and the second common flow path 22 extends in the first direction and is open to the outside of the flow path member 4 at both end portions.