Liquid Ejection Head Bubble Trap Channel Design

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Solution Overview

Problem

Existing liquid ejection heads face issues with ink leakage when detached from the recording apparatus, particularly due to tilting or impact, as the connecting portions are prone to fluid loss.

Innovation Solution

The design incorporates a liquid supplying unit with an interior channel structure that includes portions extending towards different faces, allowing bubbles to separate the ink, thereby interrupting the flow and reducing leakage when the head is removed. This structure aggregates channel members before and behind the negative pressure regulatory unit, reducing the number of components and minimizing ink leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the liquid ejection head is detachably mounted to allow easy replacement, then the ease of operation is improved, but the reliability deteriorates due to potential liquid leakage from connecting portions during detachment or impact

Engineering Contradiction:
Improveease of replacementVSAvoidliquid leakage prevention
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The interior channel is designed to extend in multiple directions (upward and downward) rather than a single linear path. This multi-dimensional channel configuration creates bubble traps at high points where bubbles naturally accumulate, preventing liquid leakage during head detachment or impact events while maintaining easy replaceability of the ejection head

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

Bubbles serve as an intermediary substance that blocks liquid flow in the channel. By intentionally designing the channel to create bubble accumulation zones, the patent uses bubbles as a passive blocking mechanism to prevent liquid leakage from the connecting portions when the head is detached or subjected to impact

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If multiple channel members are used to supply liquid, then the manufacturing precision is improved, but the device complexity increases

Engineering Contradiction:
Improvechannel structure precisionVSAvoidnumber of components
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Multiple channel members that were previously separate components are merged into a single integrated liquid supplying member. This consolidation maintains the precise multi-directional channel structure needed for bubble trapping while reducing the number of separate parts, simplifying assembly and reducing device complexity

Inventive Principle:
Principle #5Merging (Combining)

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

The solution effectively suppresses ink leakage from the connecting portions during detachment, ensuring reliable operation and reducing maintenance issues related to fluid loss.

Implementation Method 1

the interior channel includes a plurality of portions extending toward the first face and a plurality of portions extending toward the second face, thereby the liquid may be separated by bubbles

Methodology Applied
Scientific EffectBubble separation: Bubble

Data Source

PatentEP3421244B1Liquid ejection head and recording apparatus
Publication Date: 2020.06.17 CANON KK
  • EP3421244B1 patent drawingFigure 1
  • EP3421244B1 patent drawingFigure 2
  • EP3421244B1 patent drawingFigure 3A~3B

AI summary

A liquid ejection head includes a liquid ejection portion configured to eject a liquid and a liquid supplying member 2220. The liquid supplying member 2220 includes a first face 2227, a second face 2228 that is the back face of the first face 2227, a first connecting portion 2241 provided on the first face 2227 and fluidly connected to a main body 1001, a second connecting portion 2242 provided on the second face 2228 and fluidly connected to the liquid ejection portion, and an interior channel communicating the first connecting portion 2241 and the second connecting portion 2242. The interior channel includes a portion 2246 extending toward the first face 2227 and a portion 2247 extending toward the second face 2228.