Inkjet Recording Method Processing Liquid Control

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Solution Overview

Problem

Inkjet recording methods face challenges in achieving high image quality on low-absorption or non-absorption recording media due to issues like cracking, granularity, and color bleeding, particularly when the application amount of processing liquid is not optimally controlled.

Innovation Solution

An inkjet recording method where the amount of processing liquid is controlled to be equal to or less than 5 g/m² in each unit area, with an average application ratio of processing liquid to ink of 0.8 g/m² or more across multiple printing passes, ensuring a deviation of ±30% between passes, and applying the processing liquid in a manner that it is 100% or less of the ink applied, especially when the ink application is 9 g/m² or more.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the application amount of processing liquid is increased to suppress liquid deviation and granularity, then image quality is improved in regions with small ink application amount, but cracking occurs in regions with large ink application amount

Engineering Contradiction:
Improveimage qualityVSAvoidcracking
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent applies different processing liquid application amounts to different regions based on ink application amount. In regions with small ink application amount, processing liquid is applied to suppress liquid deviation and granularity. In regions with large ink application amount, processing liquid application is limited to prevent cracking. This spatial variation in processing parameters resolves the contradiction between suppressing granularity and preventing cracking.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent dynamically adjusts the processing liquid application amount as a controllable parameter based on the ink application amount in each region. By changing this parameter adaptively across different regions and printing passes, the system achieves optimal image quality without causing harmful effects like cracking or granularity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the application amount of processing liquid is increased to fix ink to recording medium, then color bleeding is suppressed, but image quality deteriorates due to cracking and granularity when not optimally controlled

Engineering Contradiction:
Improveink fixationVSAvoidimage quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent implements a feedback control mechanism where the processing liquid application amount is determined based on the ink application amount in each region. This feedback loop ensures that sufficient processing liquid is applied to fix ink and prevent color bleeding, while avoiding excessive application that would cause cracking or granularity, thus maintaining both reliability and image quality.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If processing liquid is applied in multiple printing passes to achieve uniform distribution, then image quality is improved, but deviation between passes causes cracking and unevenness

Engineering Contradiction:
Improveimage qualityVSAvoiduniformity
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The patent introduces dynamic control of processing liquid application across multiple printing passes. The application amount in each pass is adjusted based on the ink application amount and the cumulative processing liquid already applied, ensuring uniform distribution over time while preventing over-application that would cause cracking or unevenness.

Inventive Principle:
Principle #15Dynamics

4Manufacturing precision

If processing liquid application amount is varied according to ink application amount, then liquid deviation and granularity are suppressed, but control complexity increases

Engineering Contradiction:
Improveimage qualityVSAvoidcontrol mechanism
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements a self-service control mechanism where the processing liquid application amount is automatically determined based on the ink application amount data already available in the system. This self-adjusting mechanism reduces the need for external complex control systems while achieving optimal image quality through data-driven parameter adjustment.

Inventive Principle:
Principle #25Self-service

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 approach effectively suppresses cracking, granularity, and color bleeding, resulting in improved image quality on low-absorption or non-absorption recording media by optimizing the application of processing liquid in relation to ink.

Implementation Method 1

applying an ink containing at least a coloring material and a processing liquid containing at least a flocculant to a surface of a recording medium by a droplet discharge device, respectively, to coalescence the ink and the processing liquid

Methodology Applied
Scientific EffectCoagulation: Coagulation

Data Source

PatentEP3909777B1Inkjet recording method and inkjet recording apparatus
Publication Date: 2024.02.14 KONICA MINOLTA INC
  • EP3909777B1 patent drawingFigure 1~2
  • EP3909777B1 patent drawingFigure 3A~3D
  • EP3909777B1 patent drawingFigure 4A~4B

AI summary

Provided is an ink jet recording method in which an image is formed by applying an ink containing a coloring material and a processing liquid containing a flocculant to a surface of a recording medium by a droplet discharge device to coalescence, wherein an application amount of the processing liquid is changed in accordance with an application amount of the ink for each unit area, and is controlled to be 5 g/m2 or less in all of the unit areas in which the images are formed, and when the image is formed in a plurality of printing passes, an average value of the application amounts of the processing liquid in each printing pass in the unit areas in which the application amount of the processing liquid is 0.8 g/m2 or more is controlled so that a deviation when compared between the printing passes is within ± 30%.