Pretreatment Liquid Ejection Control for Ink Alignment
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Solution Overview
Problem
Existing ink jet recording methods face challenges in maintaining image quality due to variations in printing head conditions, ink viscosity, and temporal changes, leading to misalignment between pretreatment liquid and colored ink landing positions, which results in degraded image quality.
Innovation Solution
A printing method where a pretreatment liquid is ejected to form a first image with an extra portion outside the second image, with the ejection amount of the pretreatment liquid decreasing further as the position moves away from the edge of the second image, ensuring the second image is fully covered and aligned, even if out of alignment, thereby preventing image quality degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pretreatment liquid is ejected to fully cover the recording medium area, then the fixation and maximum ejection quantity are improved, but the image quality is significantly degraded when landing positions are out of alignment
Solution Approach 1:
The patent applies local quality by differentiating the ejection amount of pretreatment liquid based on position. The central region (within the second image area) receives a first ejection amount for optimal fixation, while the peripheral region (extra portion) receives a second ejection amount that is smaller than the first. This positional differentiation ensures that even when landing positions are out of alignment, the peripheral pretreatment liquid does not extend beyond the colored ink area, preventing image quality degradation while maintaining fixation in the central region.
2Manufacturing precision
If the dot diameter of pretreatment liquid is controlled for each dot, then the printing quality is improved, but the control becomes very difficult due to variations in printing head and ejection conditions
Solution Approach 1:
The patent applies parameter changes by modifying the ejection amount parameter of the pretreatment liquid based on position rather than attempting to control dot diameter for each individual dot. By changing the ejection amount parameter (first ejection amount for central region, second ejection amount for peripheral region), the patent achieves printing quality improvement while avoiding the complexity of controlling each dot's diameter individually under varying printing conditions.
3Reliability
If the pretreatment liquid extends to outside the area of colored inks, then the fixation is improved, but the image quality is significantly degraded
Solution Approach 1:
The patent applies local quality by differentiating the ejection amount of pretreatment liquid based on position. The central region (within the second image area) receives a first ejection amount for optimal fixation, while the peripheral region (extra portion) receives a second ejection amount that is smaller than the first. This positional differentiation ensures that even when landing positions are out of alignment, the peripheral pretreatment liquid does not extend beyond the colored ink area, preventing image quality degradation while maintaining fixation in the central region.
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 configuration prevents image quality degradation by allowing the second image to be formed on the extra portion of the first image, reducing the ejection amount of pretreatment liquid and delustering effects, resulting in improved image quality and uniformity.
Implementation Method 1
a liquid ejection head configured to eject liquid through its nozzles
Implementation Method 2
a step of forming a second image on the first image by ejecting a colored ink onto the first image
Data Source
AI summary
A printing method includes a step of forming a first image by ejecting a pretreatment liquid, and a step of forming a second image on the first image by ejecting a colored ink onto the first image. Here, the first image is allowed to include an extra portion by which the edge of the first image exists on the outside of the edge of the second image. Further, an amount of the ejection of the pretreatment liquid onto the extra portion per area at a position on the extra portion is allowed to be decreased further as the position is located further toward the outside from the edge of the second image.