Liquid Tank Flow Path Design for Bubble Management

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Solution Overview

Problem

Conventional liquid tanks for inkjet recording devices have complex filter structures that increase size, leading to inefficient ink supply and potential bubble-related failures, necessitating a solution to minimize size and ensure efficient ink delivery while reducing bubble emission.

Innovation Solution

A liquid tank design with a convex liquid communication flow path, an air communication flow path connected higher than the liquid communication flow path, and a filter chamber configuration that guides bubbles away from the ink supply path, along with a valve mechanism to control liquid flow and minimize air suction, effectively reducing the tank's horizontal size and preventing bubble ingress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a filter portion with bubble emission function is arranged midway through the flow path, then bubbles are emitted, but the structure becomes complicated and the filter portion increases in size

Engineering Contradiction:
Improvebubble emission functionVSAvoidstructure of filter portion
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The flow path is segmented into distinct sections: a rising flow path that extends upward and a lowering flow path that extends downward. This segmentation creates natural bubble separation zones where bubbles rise in the upward section and are prevented from entering the discharge head through the downward section, eliminating the need for complex filter structures.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The flow path is designed to extend in the vertical dimension rather than only horizontally. By creating a flow path that rises and then falls vertically, the patent utilizes the vertical space to separate bubbles from the liquid flow, reducing the horizontal size while maintaining bubble emission functionality.

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

2Reliability

If a filter portion with bubble emission function is arranged midway through the flow path, then bubbles are emitted, but the filter portion increases in size

Engineering Contradiction:
Improvebubble emission functionVSAvoidsize of filter portion
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The flow path is designed to extend in the vertical dimension rather than only horizontally. By creating a flow path that rises and then falls vertically, the patent utilizes the vertical space to separate bubbles from the liquid flow, reducing the horizontal size while maintaining bubble emission functionality.

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

Solution Approach 2:

The flow path is segmented into distinct sections: a rising flow path that extends upward and a lowering flow path that extends downward. This segmentation creates natural bubble separation zones where bubbles rise in the upward section and are prevented from entering the discharge head through the downward section, eliminating the need for complex filter structures.

Inventive Principle:
Principle #1Segmentation

3Productivity

If the liquid supply portion is positioned to efficiently supply liquid, then ink supply efficiency improves, but the tank size may increase

Engineering Contradiction:
Improveink supply efficiencyVSAvoidsize of liquid tank
Core Design Contradiction:
ProductivityVSVolume of stationary object

Solution Approach 1:

The liquid supply portion is positioned below the downstream end and extends downward toward the liquid supply port, utilizing the vertical dimension to optimize liquid flow efficiency while maintaining a compact horizontal footprint.

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

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 design enhances ink supply efficiency, reduces the risk of bubble-related failures, and minimizes the tank's horizontal size, ensuring stable operation by efficiently managing air and liquid flow within the tank.

Implementation Method 1

a liquid communication flow path through which the first liquid chamber is in fluid communication with the liquid supply portion, the liquid communication flow path forming a flow path that is upwardly convex in a mounting state where the liquid tank is mounted to the carriage

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

an air communication flow path through which the first liquid chamber is in communication with the liquid supply portion, the air communication flow path connected to the first liquid chamber in a position higher than a position of connection of the liquid communication flow path and the first liquid chamber

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Data Source

PatentEP3409478B1Liquid tank
Publication Date: 2021.07.21 SEIKO EPSON CORP
  • EP3409478B1 patent drawingFigure 1
  • EP3409478B1 patent drawingFigure 2
  • EP3409478B1 patent drawingFigure 3

AI summary

A liquid tank includes a liquid supply portion, a first liquid chamber, a liquid communication flow path and an air communication flow path. The liquid communication flow path includes an upstream end which is connected to the first liquid chamber, a rising flow path which is located on a downstream side with respect to the upstream end and which extends upward in a mounting state, a lowering flow path which is located on the downstream side with respect to the rising flow path and which extends downward in the mounting state and a downstream end which is located on the downstream side with respect to the lowering flow path and which is connected to the liquid supply portion. In the mounting state, the liquid supply portion is located lower than the downstream end and extends downward toward a liquid supply port.