Liquid Ejection Head Vent Path Bubble Collection

Solution Overview

Problem

Existing liquid ejection heads face challenges in miniaturization due to the need for a buffer chamber to collect bubbles, which limits vertical miniaturization and increases the size and weight of the recording head.

Innovation Solution

A liquid ejection head design featuring a vent path with a first area having a larger contact angle to the liquid, allowing bubbles to be collected and removed without the need for a large buffer chamber, enabling miniaturization by promoting bubble movement into the vent path and reducing the vertical size and weight of the recording head.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a buffer chamber is provided to collect bubbles in the ink supplying path, then bubble removal capability is improved, but the vertical size and weight of the recording head increases

Engineering Contradiction:

Improvebubble removal capabilityVSAvoidrecording head weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The vent path extends in the horizontal direction rather than requiring vertical space, changing the dimension in which bubble collection occurs. This allows bubble removal functionality to be achieved without increasing the vertical size or weight of the recording head, as the vent path utilizes the horizontal dimension for bubble accumulation and removal.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

A first area with larger liquid contact angle is formed on the inner surface of the vent path to create localized hydrophobicity. This local quality change promotes bubble movement into the vent path by reducing liquid adhesion in that specific region, enabling efficient bubble collection without requiring a large buffer chamber.

Inventive Principle:

Principle #3Local quality

2Reliability

If a buffer chamber is provided to collect bubbles, then bubble removal capability is improved, but the vertical size of the recording head increases

Engineering Contradiction:

Improvebubble removal capabilityVSAvoidrecording head vertical size

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The vent path extends in the horizontal direction rather than requiring vertical space, changing the dimension in which bubble collection occurs. This allows bubble removal functionality to be achieved without increasing the vertical size or weight of the recording head, as the vent path utilizes the horizontal dimension for bubble accumulation and removal.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If a buffer chamber is provided to collect bubbles, then bubble removal capability is improved, but device complexity increases

Engineering Contradiction:

Improvebubble removal capabilityVSAvoidink supplying path complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The vent path is integrated into the ink supplying path structure, merging the bubble collection function with the existing liquid supply通道. This integration reduces device complexity by combining multiple functions into a unified structure rather than adding separate components.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The vent path serves multiple functions: it acts as both a bubble collection chamber and a pressure fluctuation absorption mechanism. The first area with larger contact angle serves dual purposes of promoting bubble movement and preventing liquid leakage. This multi-functionality reduces the need for separate components, simplifying the overall device structure.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Ease of manufacture

If the vent path inner surface has uniform contact angle, then manufacturing is simplified, but bubble collection efficiency decreases

Engineering Contradiction:

Improvevent path manufacturingVSAvoidbubble collection efficiency

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

A first area with larger liquid contact angle is formed on the inner surface of the vent path to create localized hydrophobicity. This local quality change promotes bubble movement into the vent path by reducing liquid adhesion in that specific region, enabling efficient bubble collection without requiring a large buffer chamber.

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 design effectively miniaturizes the liquid ejection head in the vertical direction, reduces the load on the carriage, and extends the life of the moving mechanism by efficiently collecting bubbles and absorbing pressure fluctuations.

Implementation Method 1

An inner surface of the vent path extending along the horizontal direction includes a first area formed thereon and having a larger contact angle to the liquid than an inner surface of the supplying path

Methodology Applied

Scientific EffectContact angle: Wetting

Data Source

PatentUS10569565B2Liquid ejection head and liquid ejection apparatus

Publication Date: 2020.02.25 CANON KK

AI summary

A liquid ejection head including a supplying path supplying a liquid ejected from an ejection port includes a vent path branching from the supplying path to extend along a horizontal direction, the vent path enabling collection of bubbles mixed into the liquid. An inner surface of the vent path extending along the horizontal direction includes an area formed thereon and having a greater contact angle to the liquid than that of an inner surface of the supplying path.