Post Processing Device Sheet Curling Suppression

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Solution Overview

Problem

Inkjet printing leads to paper sheet curling due to ink absorption and drying, causing misalignment and transportation failures when multiple sheets are processed sequentially, as earlier curled sheets can catch later sheets, resulting in jamming and deformation.

Innovation Solution

A post-processing device with a suppressing unit that adjusts the gap between rollers or uses air blowing to restrict curling, and a controller to manage the suppression unit's operation based on detection of jamming and transportation status, ensuring proper alignment and flattening of sheets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If inkjet printing is performed on paper sheets, then image formation is achieved, but paper sheet curling occurs due to ink absorption and drying

Engineering Contradiction:
Improveimage formation qualityVSAvoidpaper sheet flatness
Core Design Contradiction:
Manufacturing precisionVSShape

Solution Approach 1:

The patent applies preliminary action by performing flattening treatment on the paper sheet immediately after inkjet printing while the sheet is still in the transportation path. The flattening unit (including rollers or pressing mechanisms) acts on the curled sheet before it reaches the post-processing device, preventing the curling from causing misalignment or transportation failures in subsequent processing stages.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If multiple paper sheets are processed sequentially on a processing tray, then post processing can be performed, but misalignment and transportation failures occur due to curled sheets catching later sheets

Engineering Contradiction:
Improvepost processing throughputVSAvoidtransportation reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system performs preliminary flattening action on each paper sheet in the transportation path between the inkjet printer and post-processing device. This preliminary treatment ensures that sheets are flat before being loaded onto the processing tray, preventing the catching and misalignment problems that would reduce transportation reliability and cause processing failures.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary flattening unit that acts as a mediator between the inkjet printing stage and the post-processing stage. This intermediate treatment device (with flattening rollers or pressing mechanisms) corrects the curling issue caused by inkjet printing before the sheets enter the post-processing transportation system, thereby ensuring smooth sequential processing without misalignment or catching problems.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If transportation is stopped to resolve jamming or cover opening, then the situation is solved, but deformation amount of mounted medium increases

Engineering Contradiction:
Improvetransportation stabilityVSAvoidmedium deformation
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The system applies preliminary flattening action continuously or periodically on sheets in the transportation path, even during temporary stops for jam resolution or cover opening. This ensures that when transportation resumes, the sheets remain flat and properly aligned, minimizing deformation that would occur during extended stops.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The flattening treatment operates continuously or periodically throughout the transportation process, maintaining sheet flatness even when transportation is temporarily stopped. This continuous useful action (flattening) counteracts the deformation that occurs during stops, ensuring sheets remain suitable for processing when transportation resumes.

Inventive Principle:
Principle #20Continuity of useful 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

Effectively prevents curling and subsequent transportation failures by restricting sheet deformation, maintaining sheet alignment and reducing jamming occurrences, thereby ensuring smooth processing of printed sheets.

Implementation Method 1

uses air blowing to restrict curling

Methodology Applied
Scientific EffectAir blowing:

Data Source

PatentEP3269554B1Post processing device and printing system
Publication Date: 2020.10.07 SEIKO EPSON CORP
  • EP3269554B1 patent drawingFigure 1
  • EP3269554B1 patent drawingFigure 2
  • EP3269554B1 patent drawingFigure 3

AI summary

There is provided a post processing device including a mounting portion on which a medium is temporarily mounted, a post processing unit that performs post processing on the medium mounted on the mounting portion, a discharging tray on which the medium is stacked after being discharged, and a suppressing unit that suppresses deformation of the medium mounted on the mounting portion.