Ink Jet Recording Undercoating for Uniformity

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Solution Overview

Problem

Ink jet recording methods face challenges in achieving uniformity and preventing bleeding or unevenness in line width and color on various recording media, especially when using low-resolution head units or small ink amounts, due to ink droplet coalescence and varying absorption properties of the media.

Innovation Solution

The method involves applying an undercoating liquid containing an oligomer and partially curing it on the recording medium, followed by ejecting ink droplets onto the partially cured layer to prevent coalescence and maintain dot shape, ensuring high density and uniformity across the image.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If ink droplets are ejected onto non-absorbing recording medium, then image formation speed is improved, but image bleeding and unevenness occur due to droplet coalescence

Engineering Contradiction:
Improveimage formation speedVSAvoidimage uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies a radiation-curable undercoating liquid to the recording medium before ejecting the ink droplets. This undercoating layer is then partially cured by radiation to create a surface that prevents ink droplet coalescence while allowing rapid image formation. The preliminary preparation of the undercoating layer resolves the contradiction by enabling both high-speed printing and image uniformity on non-absorbing media.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The radiation-curable undercoating liquid serves as an intermediary layer between the ink droplets and the non-absorbing recording medium. This intermediate layer provides the necessary surface properties to prevent droplet coalescence and image bleeding, while allowing the ink to be firmly fixed. The undercoating layer mediates the interaction between ink and substrate, resolving the uniformity issue without sacrificing printing speed.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If small ink amounts are used with low-resolution head units, then device cost is reduced, but image density and uniformity deteriorate due to dot coalescence

Engineering Contradiction:
Improvedevice costVSAvoidimage density
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent prepares a radiation-curable undercoating layer on the recording medium before ink ejection. This preliminary treatment creates a surface that allows even distribution and firm fixation of small ink droplets from low-resolution head units. The undercoating layer ensures that dots maintain their shape and do not coalesce, achieving high image density and uniformity despite using cost-effective, low-resolution printing equipment.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If ink is ejected onto varying recording media, then adaptability is improved, but image uniformity worsens due to different absorption properties

Engineering Contradiction:
Improvemedia compatibilityVSAvoidimage uniformity
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The radiation-curable undercoating liquid serves as a universal preparatory layer that can be applied to various types of recording media (absorbing, non-absorbing, transparent, opaque). This undercoating layer provides consistent surface properties across different media types, enabling uniform ink fixation and preventing coalescence regardless of the underlying substrate's absorption characteristics. The multi-functional undercoating layer resolves the contradiction between media adaptability and image uniformity.

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

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 image bleeding and unevenness, allowing for high-density, clear image reproduction with low dot density and small ink amounts, particularly effective on non-permeable media and using low-cost, low-resolution head units.

Implementation Method 1

irradiating with actinic energy rays or heat to half-cure the applied undercoating liquid

Methodology Applied
Scientific EffectPhotopolymerisation: Photopolymerisation

Implementation Method 2

irradiating with actinic energy rays or heat to half-cure the applied undercoating liquid; the ink droplets contain a polymerizable or crosslinkable material for formation of an image

Methodology Applied
Scientific EffectPhotopolymerisation: Photopolymerisation

Data Source

PatentEP1902849B1Ink jet recording method and ink jet recording device
Publication Date: 2012.08.15 FUJIFILM CORP
  • EP1902849B1 patent drawingFigure 1A~1D
  • EP1902849B1 patent drawingFigure 2
  • EP1902849B1 patent drawingFigure 3A~3B

AI summary

An ink jet recording method comprising: applying an undercoating liquid containing an oligomer onto a recording medium; partially curing the undercoating liquid that has been applied onto the recording medium; and recording an image by ejecting an ink that is curable by irradiation of actinic energy onto the partially cured undercoating liquid. According to the invention, an image having excellent uniformity can be recorded on various types of recording media, irrespective of the type thereof, ink bleeding and unevenness in line width or color due to coalescence of ink droplets can be effectively suppressed, and an image with high density and a uniform dot diameter can be recorded when the image has low dot density such as low image resolution or image density.