Inkjet Decurler Adjusting Bending Amount by Local Ink Ejection Rate

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Solution Overview

Problem

Inkjet recording apparatuses face issues with uneven curling of sheets due to varying ink ejection rates across different areas, leading to insufficient reduction of curling in specific areas despite reducing curling in other areas.

Innovation Solution

An inkjet recording apparatus with a decurler mechanism that adjusts the bending amount of the sheet by changing the position of rollers and pinching force to effectively reduce curling, using a control device to calculate and apply specific bending amounts based on ink ejection rates and sheet types.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a stopping time is determined and the conveyance of the sheet is stopped to dry ink and decrease curling, then curling in the sheet is reduced, but unevenness in the strength of curling between areas remains because ink ejection rates vary across different areas

Engineering Contradiction:
Improvecurling uniformityVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies local quality by determining stopping times specific to each area of the sheet based on local ink ejection rates. The control device divides the sheet into multiple areas and calculates individual stopping times for each area, allowing differential treatment of regions with different ink coverage to achieve uniform curling reduction across the entire sheet.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements dynamics by making the stopping time a variable parameter that changes based on the ink ejection rate in each area. Rather than using a fixed stopping time for the entire sheet, the system dynamically adjusts the stopping duration for each area to match its specific ink coverage characteristics, enabling effective curling control despite varying ink application.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If the curling of the sheet is reduced by stopping conveyance, then overall curling decreases, but specific areas with higher ink ejection rates remain curled

Engineering Contradiction:
Improvecurling reduction effectivenessVSAvoidprocessing time
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent ensures effective curling reduction in all areas by applying local quality through area-specific stopping time determination. Each area's stopping time is calculated based on its ink ejection rate, guaranteeing that even areas with high ink coverage achieve sufficient curling reduction while avoiding unnecessary stopping in areas with lower ink coverage.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent applies partial or excessive action by determining stopping times that are sufficient for each local area's curling reduction needs. The control device calculates stopping times that may be longer than necessary for some areas but ensures adequate treatment for all areas, particularly those with higher ink ejection rates, thereby achieving complete curling reduction across the sheet.

Inventive Principle:
Principle #16Partial or excessive 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 apparatus effectively reduces curling by adjusting the bending amount of the sheet to match the strength of curling in different areas, ensuring uniformity and preventing excessive bending, thereby improving the printing process.

Implementation Method 1

a decurler mechanism that adjusts the bending amount of the sheet by changing the position of rollers and pinching force to effectively reduce curling

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP3524431B1Inkjet recording device
Publication Date: 2023.01.04 KYOCERA DOCUMENT SOLUTIONS INC
  • EP3524431B1 patent drawingFigure 1
  • EP3524431B1 patent drawingFigure 2
  • EP3524431B1 patent drawingFigure 3

AI summary

An inkjet recording apparatus (1) includes an image forming section (40), a decurler (20), a changing section (50), a first calculating section (72), storage (60), a second calculating section (73), and a controller (75). The image forming section (40) ejects ink onto a sheet (S). The decurler (20) bends the sheet (S). The changing section (50) changes a bending amount of the sheet (S). The first calculating section (72) calculates an ink ejection rate (α) to the sheet (S) for each of areas of the sheet (S). The storage (60) stores therein first bending information (62) indicating a first target bending amount (β) of a specific area of the sheet (S) corresponding to the ink ejection rate (α) to the specific area. The second calculating section (73) calculates a second target bending amount of each of the areas. The controller (75) controls the changing section (50) based on the second target bending amounts.