Ink Filter Passive De-aeration via Air-Permeable Polymer Vent

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Solution Overview

Problem

Inkjet printers face issues with air bubbles blocking ink filters, leading to reduced filter efficacy and requiring inconvenient and time-consuming replacements, especially since de-aeration pumps increase cost and complexity.

Innovation Solution

An ink filter with a filter chamber, inlet, outlet, and vent port, featuring a closed vent chamber with air-permeable polymer tubing that allows passive air bubble removal without the need for a de-aeration pump, utilizing air-permeable polymer with sufficient oxygen permeability to diffuse air bubbles out at positive hydrostatic pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a de-aeration pump is used to remove air bubbles from the ink filter, then air bubble removal is effective, but the cost and complexity of the ink delivery system increase

Engineering Contradiction:
Improveair bubble removal effectivenessVSAvoidink delivery system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the air bubble removal function from the main ink delivery system by creating a separate, passive vent chamber that is disconnected during normal operation. The vent chamber is only activated when air bubbles need to be removed, allowing effective air removal without continuously complicating the ink delivery system.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The vent chamber is designed to be self-activating through pressure differential. When air bubbles accumulate and increase pressure in the filter chamber, the pressure automatically opens the connection to the vent chamber, allowing air to escape without requiring external control or additional active components.

Inventive Principle:
Principle #25Self-service

2Reliability

If the ink filter is blocked with air bubbles, then print quality deteriorates, but manual replacement is inconvenient and time-consuming

Engineering Contradiction:
Improveprint qualityVSAvoidfilter replacement time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The vent chamber provides self-service air removal functionality that automatically restores filter performance without user intervention. When air bubbles block the filter and degrade print quality, the pressure differential automatically activates the vent chamber to remove air bubbles, maintaining print quality without requiring manual filter replacement.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system discards accumulated air bubbles through the vent chamber and recovers filter performance automatically. Instead of requiring complete filter replacement when air bubbles accumulate, the system selectively removes only the harmful air bubbles while retaining the functional filter material, thereby recovering print quality without time-consuming replacement.

Inventive Principle:
Principle #34Discarding and recovering

3Adaptability or versatility

If air is introduced into the ink delivery system via printhead depriming operations, then printhead can be replaced, but air bubbles circulate and become trapped in the ink filter

Engineering Contradiction:
Improveprinthead replaceabilityVSAvoidink filter performance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The vent chamber extracts air bubbles from the ink filter separately from the main ink circulation path. This allows printhead depriming operations to proceed normally for printhead replacement while the vent chamber simultaneously removes introduced air bubbles from the filter, preventing them from circulating and blocking the filter.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The vent chamber acts as an intermediary between the filter chamber and the atmosphere. It provides a dedicated pathway for air bubbles introduced during printhead operations to escape, mediating between the need for printhead replaceability and the need to maintain ink filter performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables effective passive recovery of air bubbles from the ink filter, reducing the need for replacements and maintaining print quality by allowing air bubbles to diffuse out, thus extending the filter's lifespan and simplifying the ink delivery system.

Implementation Method 1

the vent chamber has at least one wall exposed to atmosphere comprised of an air-permeable polymer

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

the polymer tubing extends generally upwards from the vent port and defines sidewalls of the vent chamber

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentEP3651994B1Ink filter with passive de-aeration
Publication Date: 2021.03.17 MEMJET TECH LTD
  • EP3651994B1 patent drawingFigure 1
  • EP3651994B1 patent drawingFigure 2~3

AI summary

An ink filter for an ink delivery system. The ink filter includes: a filter chamber having a filter inlet port, a filter outlet port and a vent port, the vent port being positioned in a roof of the filter chamber; a filter material positioned between the filter inlet port and the filter outlet port; and a closed vent chamber connected to the vent port. The vent chamber has wall exposed to atmosphere formed of an air-permeable polymer.