Liquid Discharge Head Flow Path Segmentation for Bubble Prevention

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Solution Overview

Problem

Conventional liquid discharge heads experience variations in liquid flow quantity between first and second common flow paths, leading to potential clogging and bubble buildup, which affects discharge performance and stability.

Innovation Solution

The liquid discharge head is designed with first and second common flow paths linked via connection flow paths outside the pressure chamber range, reducing pressure differences and stabilizing liquid circulation by adjusting the resistance and configuration of these paths to improve flow stability and reduce clogging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If liquid flows from first common flow paths to second common flow paths through pressure chambers, then liquid circulation is maintained and clogging is prevented, but flow quantity varies between different flow paths leading to instability

Engineering Contradiction:
Improveliquid circulation stabilityVSAvoidflow quantity uniformity
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The invention divides the common flow paths into multiple segments (first common flow paths and second common flow paths) that are alternately arranged. By segmenting the flow paths and creating multiple circulation routes through pressure chambers, the system achieves more uniform liquid distribution and prevents clogging while maintaining stable circulation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces connection flow paths with different configurations and resistances to create asymmetric flow characteristics. Specifically, connection flow paths are designed with varying lengths, positions, and resistance values to balance the flow quantity between first and second common flow paths, thereby achieving uniform liquid circulation despite the asymmetric arrangement of pressure chambers.

Inventive Principle:
Principle #4Asymmetry

2Reliability

If connection flow paths are added to link first and second common flow paths, then flow stability is improved and clogging is reduced, but device complexity increases

Engineering Contradiction:
Improveflow path stabilityVSAvoidflow path configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention merges the functions of multiple flow paths by having first and second common flow paths alternately connected through pressure chambers and connection flow paths. This integration creates a unified circulation system where liquid can flow through multiple routes, improving stability without requiring completely separate systems for each function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The pressure chambers serve multiple functions: they act as discharge units for liquid ejection, circulation nodes connecting first and second common flow paths, and flow balancing elements. This multi-functionality reduces the need for additional dedicated components, thereby limiting the increase in device complexity while achieving flow stability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If pressure differences are reduced in common flow paths, then liquid circulation stability is improved, but discharge performance may be affected

Engineering Contradiction:
Improvecirculation stabilityVSAvoiddischarge performance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention applies different flow resistance characteristics to different regions of the flow path system. Connection flow paths are designed with specific resistance values that differ from the main common flow paths, allowing local optimization of flow distribution. This enables reduced pressure differences for stable circulation while maintaining sufficient pressure for effective liquid discharge at the nozzles.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3248783B1Liquid discharge head and recording device using same
Publication Date: 2021.07.07 KYOCERA CORP
  • EP3248783B1 patent drawingFigure 1(a)~1(b)
  • EP3248783B1 patent drawingFigure 2(a)~2(b)
  • EP3248783B1 patent drawingFigure 3

AI summary

A liquid discharge head of the present disclosure includes a flow path member 4 having a plurality of discharge holes 8, a plurality of pressure chambers 10, a plurality of first common flow paths 20, and a plurality of second common flow paths 24, and a plurality of pressure sections 50. The first common flow paths 20 and the second common flow paths 24 are linked through a connection flow path 25 outside a connection range C, the connection range C being linked through the pressure chambers 10. The flow path member 4 is configured by laminating a plurality of flat plates 4a to 41. The connection flow path 25 includes holes and/or grooves disposed in plates 4a to 4e, and 4j to 41 other than the common flow path plates 4f to 4i that constitute the first common flow paths 20 and the second common flow paths 24.