Inkjet Recording Device Overlapping Head Complementary Output

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Solution Overview

Problem

Existing liquid ejection devices face issues with concentration irregularities in images formed on a medium due to deviations in the attachment positions of heads, leading to visible unevenness in gloss.

Innovation Solution

An inkjet recording device with overlapping head units that complementarily discharge ink in specific operation rates within an overlapping range, ensuring that ink droplets from upstream and downstream heads are integrated, reducing the difference in gloss between overlapping and nonoverlapping areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple recording heads are used to increase productivity, then the printing width and speed are improved, but concentration irregularities and gloss unevenness occur due to attachment position deviations

Engineering Contradiction:
Improveprinting width and speedVSAvoidconcentration uniformity and gloss uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent divides the printing area into overlapping regions and non-overlapping regions, and further segments the overlapping regions into first overlapping parts and second overlapping parts. Different recording heads are assigned to different segments with complementary output operations, allowing precise control of ink discharge in each segment to compensate for attachment position deviations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different output operations to different regions: in non-overlapping regions, recording heads perform normal output operations, while in overlapping regions, recording heads perform complementary output operations. This local differentiation ensures uniform concentration and gloss across the entire printed area despite head position variations.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If heads are attached with position deviations, then device assembly becomes easier, but image quality deteriorates due to visible gloss differences

Engineering Contradiction:
Improvehead assembly easeVSAvoidimage quality and gloss uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent implements dynamic control of output operations based on the type of region (non-overlapping, first overlapping, second overlapping). The controller adjusts the output operation of each recording head according to its position and the region it serves, enabling the system to adapt to attachment position deviations and maintain uniform image quality.

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If complementary output operation is implemented in overlapping areas, then gloss unevenness is reduced, but device complexity increases

Engineering Contradiction:
Improvegloss uniformityVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent pre-defines the segmentation of the printing area into non-overlapping regions and overlapping regions (first and second types) before printing begins. The controller is configured to automatically apply the appropriate output operation based on the region type, eliminating the need for real-time complex calculations and simplifying the control system while maintaining gloss uniformity.

Inventive Principle:
Principle #10Preliminary 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

The solution effectively reduces unevenness in gloss across the image, making the difference between overlapping and nonoverlapping areas invisible, thereby enhancing image quality.

Implementation Method 1

recording elements 243 for discharging ink which changes a phase between a solid and a liquid

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP3351386B1Inkjet recording device and inkjet recording method
Publication Date: 2020.10.21 KONICA MINOLTA INC
  • EP3351386B1 patent drawingFigure 1~2
  • EP3351386B1 patent drawingFigure 3
  • EP3351386B1 patent drawingFigure 4

AI summary

Provided are an inkjet recording device and an inkjet recording method that can suppress uneven brightness in images formed by a long recording means that has a plurality of recording heads. The present invention is provided with a recording control means that causes phase-changing ink to be discharged from a plurality of recording elements, which are provided to a plurality of recording heads, onto a recording medium that moves relative to one movement direction. The plurality of recording heads are arranged so as to overlap in a width direction, which is orthogonal to the one movement direction, in an end-section vicinity range. The recording control means uses the respective recording elements of the overlapping recording heads to perform a complementary output operation within the end-section vicinity range. The complementary output operation is set to monotonically increase so as to include a transitional region in which a downstream-side operation rate, which is the proportion of output operations being performed by the recording elements of a downstream-side recording head, gradually increases within the end-section vicinity range from an end-section side of the downstream-side recording head to at least a prescribed lower-limit value greater than 0.