Valve Unit Sediment Expelling for Inkjet Clogging Prevention

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Solution Overview

Problem

Inkjet printing apparatuses face issues with clogging and discharge defects due to the formation of low-solubility component deposits in the ink path, which can lead to sediment accumulation and foreign substances causing blockages in the recording head.

Innovation Solution

A printing apparatus with a valve unit that includes a sediment expelling section positioned below the second chamber, allowing sediment to settle and be easily expelled, combined with a control unit that manages the expelling process during ink discharge stops or flushing operations, ensuring sediment is removed before printing starts, thereby preventing clogging and maintaining ink flow stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If deep color inks with high percentage of low-solubility components are used, then color depth and quality are improved, but sediment formation and clogging in the recording head increase

Engineering Contradiction:
Improveimage qualityVSAvoidclogging
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the harmful sediment from the ink flow path by introducing a separate sediment collection chamber that collects low-solubility components before they reach the recording head, thereby maintaining both deep color quality and preventing clogging

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary sediment collection chamber between the ink supply and recording head that acts as a buffer zone, allowing low-solubility components to settle out before the ink reaches the nozzles, thus protecting the recording head while maintaining ink quality

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If sediment collection chamber is added to the valve unit, then sediment removal capability is improved, but device complexity increases

Engineering Contradiction:
Improveclogging preventionVSAvoidvalve unit structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the sediment collection chamber with the existing valve unit structure, integrating multiple functions (valve operation and sediment collection) into a single compact assembly, thereby improving reliability without proportionally increasing device complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The valve unit is designed to serve multiple functions: controlling ink flow to the recording head and simultaneously collecting sediment. This multi-functionality reduces the need for separate dedicated sediment removal devices, balancing reliability improvement with acceptable complexity

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

3Reliability

If expelling operation is performed during printing, then sediment removal is improved, but ink discharge stability deteriorates

Engineering Contradiction:
Improvesediment removalVSAvoidink discharge stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent performs sediment expelling operations preliminarily, before printing begins or during idle periods when no ink is being discharged. This timing strategy allows complete sediment removal without interfering with ink discharge stability during actual printing operations

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements periodic sediment expelling operations at scheduled intervals (before printing starts, during flushing operations, or after printing ends) rather than continuously during printing. This periodic approach maintains ink discharge stability while still achieving effective sediment removal

Inventive Principle:
Principle #19Periodic action

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

Prevents sediment from flowing into the discharge unit, reducing clogging and discharge defects, and ensures stable ink discharge by expelling sediment before printing, thus maintaining the precision and quality of color printing.

Implementation Method 1

an expelling unit, which, in a case where sediment is formed in the second chamber, expels the sediment by suctioning the sediment

Methodology Applied
Scientific EffectSuction: Suction

Implementation Method 2

The sediment settles downward in the second chamber, and thus positioning the expelling unit below the second chamber ensures that the sediment is quickly expelled from the expelling unit

Methodology Applied
Scientific EffectSedimentation: Sedimentation

Data Source

PatentEP3263346B1Valve unit, printing apparatus, and printing method
Publication Date: 2021.10.06 SEIKO EPSON CORP
  • EP3263346B1 patent drawingFigure 1
  • EP3263346B1 patent drawingFigure 2
  • EP3263346B1 patent drawingFigure 3

AI summary

Provided are a valve unit, a printing apparatus, and a printing method capable of preventing sediment arising in the valve unit from flowing toward a discharge unit. The valve unit is used in a printing apparatus including a reservoir unit that holds ink, a discharge unit configured to discharge the ink, and a flow channel that connects the reservoir unit to the discharge unit and through which the ink flows from the reservoir unit to the discharge unit. The valve unit is disposed partway along the flow channel, and includes: a first chamber that configured to communicate with the reservoir unit; a second chamber configured to communicate with the discharge unit; a switching valve that switches between allowing and cutting off a flow of ink from the first chamber to the second chamber; and an expelling unit configured to expel sediment from the second chamber by suctioning the sediment.