Inkjet Recording Head Gloss Uniformity via Phased Discharge Control

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Solution Overview

Problem

Inkjet recording devices with long head units having staggered recording heads experience unevenness in gloss between overlapping and non-overlapping ranges due to limited freedom in ink discharge patterns, leading to differences in surface shape and gloss of the recorded image.

Innovation Solution

The device employs a recording control mechanism that adjusts the output operations of upstream and downstream recording elements to ensure continuous operation by downstream elements and non-continuous operation by upstream elements, with a phased discharge pattern that aligns the surface shape of ink in overlapping ranges with non-overlapping ranges, using a phased discharge and relative movement speed to synchronize ink solidification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If recording heads are arranged in a staggered manner with overlapping ranges to improve recording rate, then productivity is improved, but unevenness in gloss between overlapping and non-overlapping ranges occurs

Engineering Contradiction:
Improverecording rateVSAvoidgloss uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by differentiating the discharge patterns of upstream and downstream recording elements in the overlapping range. Downstream recording elements perform continuous output operations while upstream recording elements perform non-continuous output operations, creating locally optimized discharge patterns that ensure uniform ink solidification and consistent gloss across the entire recording surface, including the previously problematic overlapping ranges.

Inventive Principle:
Principle #3Local quality

2Reliability

If recording elements continuously perform output operations in overlapping ranges to stabilize ink discharge, then ink discharge property is stabilized, but freedom degree of ink discharge pattern is reduced

Engineering Contradiction:
Improveink discharge stabilityVSAvoidink discharge pattern freedom
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamics by making the output operation pattern adaptive rather than static. The control device dynamically determines which recording elements perform continuous or non-continuous output operations based on their position (upstream or downstream) and the specific overlapping range, allowing the system to maintain ink discharge stability while preserving flexibility in discharge patterns through conditional, position-dependent operation modes.

Inventive Principle:
Principle #15Dynamics

3Loss of time

If downstream recording elements discharge ink after upstream elements in overlapping ranges, then ink solidification time is sufficient, but surface shape of discharged ink is affected by solidified ink from upstream elements

Engineering Contradiction:
Improveink solidification timeVSAvoidink surface shape
Core Design Contradiction:
Loss of timeVSShape

Solution Approach 1:

The patent applies preliminary action by having upstream recording elements discharge ink first, allowing it to spread and solidify on the recording medium before downstream recording elements discharge their ink. This sequential timing ensures that when downstream ink is discharged, the upstream ink has already solidified, preventing unwanted interaction between the two ink streams while maintaining sufficient solidification time for consistent surface shape formation.

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

This approach effectively suppresses unevenness in gloss between overlapping and non-overlapping ranges, achieving a consistent surface shape and reduced gloss variation across the recorded image.

Implementation Method 1

ink, which changes a phase between a solid and a liquid

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP3597432B1Inkjet recording device and inkjet recording method
Publication Date: 2022.07.27 KONICA MINOLTA INC
  • EP3597432B1 patent drawingFigure 1~2
  • EP3597432B1 patent drawingFigure 3
  • EP3597432B1 patent drawingFigure 4A~4C

AI summary

Provided are an inkjet recording device and an inkjet recording method that can suppress uneven gloss in images recorded by a long recording means having a plurality of recording heads. The inkjet recording device comprises a recording control means that discharges phase-changing ink from a plurality of recoding elements provided in a plurality of recording heads, discharging same on to a recording medium that moves relatively. Each recording head is arranged at a position at which the arrangement range of the recording elements in the width direction overlaps another recording head in a proximity range from an end section. The recording control means: selects one of the recording elements that have corresponding positions in the width direction in a pair of recording heads, within a set range in the proximity range, and performs an output operation; and determines the order of execution of the output operation by downstream-side recording elements and upstream-side recording elements having corresponding positions in the width direction, determining same such that the output operation by each recording element in a downstream-side recording head continues at least twice and at least some of the output operations by recording elements in an upstream-side recording head are not continuous.