Inkjet Printer Oxygen Control for LED Curing

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Solution Overview

Problem

Current inkjet printing systems face challenges in achieving efficient curing with reduced oxygen levels, as existing solutions require large footprints, high power consumption, and excessive heat, while maintaining acceptable print quality and interlayer adhesion.

Innovation Solution

A compact, in-line printing apparatus using light-emitting diodes (LEDs) with a controlled atmosphere of inert gases, such as nitrogen, to cure ink, allowing for dynamic adjustment of oxygen and inert gas levels to optimize surface characteristics and adhesion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional high-power UV curing systems are used to cure ink, then curing efficiency is improved, but power consumption and heat production increase excessively

Engineering Contradiction:
Improvecuring efficiencyVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent introduces an inert gas (nitrogen or carbon dioxide) atmosphere in the curing chamber to enhance UV curing efficiency. The inert atmosphere prevents oxygen inhibition of the photopolymerization reaction, allowing complete curing even with lower power LED UV sources. This resolves the contradiction by enabling efficient curing through atmospheric control rather than relying solely on high power input.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

Solution Approach 2:

The patent replaces traditional high-power mercury arc lamp curing systems with LED UV curing sources. LEDs consume significantly less power and generate less heat while providing sufficient curing energy, especially when combined with the inert atmosphere that eliminates oxygen inhibition. This substitution directly addresses the power consumption and heat production issues.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If high-power UV curing systems are used to cure ink, then curing efficiency is improved, but heat production becomes excessive

Engineering Contradiction:
Improvecuring efficiencyVSAvoidheat production
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The inert gas atmosphere enables complete photopolymerization by eliminating oxygen inhibition, allowing lower-power LED UV sources to achieve full curing. This reduces the need for high-power lamps that generate excessive heat, thereby resolving the heat production problem while maintaining curing efficiency.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

Solution Approach 2:

The patent substitutes mercury arc lamps with LED UV sources. LEDs inherently generate far less heat than traditional high-power UV lamps while providing sufficient curing energy, especially in an inert atmosphere. This substitution directly reduces heat production while maintaining or improving curing efficiency.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If oxygen levels are not controlled during curing, then equipment complexity is reduced, but cure speed decreases due to oxygen inhibition

Engineering Contradiction:
Improveatmosphere control systemVSAvoidcure speed
Core Design Contradiction:
Device complexityVSSpeed

Solution Approach 1:

The patent introduces a relatively simple inert gas atmosphere system (nitrogen or carbon dioxide) that effectively eliminates oxygen inhibition of the UV curing process. This modest addition to the curing system dramatically increases cure speed by preventing the formation of an uncured skin on the ink surface, while maintaining acceptable system complexity.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

Solution Approach 2:

The patent changes the atmospheric composition parameter from ambient air (21% oxygen) to inert gas atmosphere (0-5% oxygen). This parameter change eliminates oxygen inhibition of photopolymerization, enabling complete and rapid curing throughout the ink layer without requiring complex control systems.

Inventive Principle:
Principle #35Parameter changes

4Speed

If controlled atmosphere is introduced to enhance curing, then cure speed is improved, but device complexity increases

Engineering Contradiction:
Improvecure speedVSAvoidatmosphere control system
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent implements a relatively simple inert gas atmosphere system using nitrogen or carbon dioxide gas sources with flow control. This straightforward approach to atmosphere control effectively eliminates oxygen inhibition and dramatically improves cure speed without requiring complex multi-component control systems, maintaining good manufacturability.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

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 solution enables efficient curing with reduced power consumption and heat production, achieving high-quality prints with improved interlayer adhesion and surface finish by controlling oxygen levels in the curing process.

Implementation Method 1

an array of light-emitting diodes (LED) to cure the ink

Methodology Applied
Scientific EffectLight-emitting diode: Light Emitting Diode

Implementation Method 2

curing the ink by exposing it to electromagnetic radiation from the LED

Methodology Applied
Scientific EffectPhotopolymerisation: Photopolymerisation

Implementation Method 3

reducing oxygen that reduces cure speed as a result of competing triplet and radical quenching reactions

Methodology Applied
Scientific EffectOxygen inhibition:

Data Source

PatentEP2652173B1Inkjet printer with controlled oxygen levels
Publication Date: 2019.08.14 ELECTRONICS FOR IMAGING INC
  • EP2652173B1 patent drawingFigure 1A~1B
  • EP2652173B1 patent drawingFigure 2
  • EP2652173B1 patent drawingFigure 3A~3B

AI summary

An in-line printing apparatus with an inerting station that delivers an atmosphere having an optimal composition to inert a layer of ink such that LED radiation adequately cures the ink. A process for configuring a printing environment for delivering an atmosphere having an optimal composition to inert a layer of ink such that LED radiation adequately cures the ink.