Image Formation Position Adjustment for Continuous Paper Shrinkage

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Solution Overview

Problem

Conventional image forming apparatuses face challenges in maintaining accurate image positioning on continuous paper due to shrinkage caused by heat during the fixing process, leading to inconsistent image intervals and potential misalignment.

Innovation Solution

An image forming apparatus equipped with a detector to identify marks on continuous paper, an image former to form images based on detected marks, and a controller that adjusts the image formation position according to the image formation state, using set values to account for potential shrinkage and ensure precise positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an image is formed on continuous paper using heat fixing, then the image is fixed onto the paper, but the continuous paper shrinks due to heat causing position misalignment

Engineering Contradiction:
Improveimage fixationVSAvoidimage position accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by detecting the mark position on the continuous paper before the heat fixing process, and pre-calculating the corrected image formation position based on expected shrinkage. This allows the system to compensate for shrinkage effects before they occur, ensuring accurate image positioning despite the subsequent paper contraction during heat fixing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using a detection device to monitor the actual position of marks on the continuous paper, and using this detected information to adjust and correct the image formation position. The control device receives detection results and modifies the imaging parameters accordingly, creating a closed-loop system that compensates for shrinkage-induced position deviations.

Inventive Principle:
Principle #23Feedback

2Device complexity

If image formation is performed based on shrunk position after fixing, then the process is simplified, but images cannot be formed at appropriate positions

Engineering Contradiction:
Improveprocess complexityVSAvoidimage position accuracy
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

Instead of waiting for shrinkage to occur and then adjusting, the system performs preliminary detection of mark positions and pre-calculates the corrected image formation positions before heat fixing. This preliminary action maintains positioning accuracy without requiring complex post-fixing adjustments.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the parameter of image formation position based on detected mark positions and expected shrinkage characteristics. The control device modifies positioning parameters dynamically, adjusting where images are formed on the paper to compensate for anticipated shrinkage, thereby maintaining accuracy without increasing overall process complexity.

Inventive Principle:
Principle #35Parameter changes

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

Enables accurate and consistent image formation at appropriate positions even when continuous paper shrinks during the heat-fixing process, maintaining uniform image intervals and improving operational efficiency.

Implementation Method 1

a detector that detects a mark on the continuous paper conveyed by the conveyer

Methodology Applied
Scientific EffectOptical detection: Photoelectric Effect

Implementation Method 2

an image former that is provided on a subsequent stage side of the detector and forms an image on the continuous paper

Methodology Applied
Scientific EffectElectrophotography: Photoconductivity

Data Source

PatentEP3474077B1Image forming apparatus
Publication Date: 2021.11.24 KONICA MINOLTA INC
  • EP3474077B1 patent drawingFigure 1
  • EP3474077B1 patent drawingFigure 2~3
  • EP3474077B1 patent drawingFigure 4

AI summary

To provide an image forming apparatus (1) capable of forming an image at an appropriate position. An image forming apparatus (1), includes: a conveyer (21) that conveys continuous paper (P) through a conveying path (22); a detector (5) that detects a mark (M) on the continuous paper (P) conveyed by the conveyer (21); an image former (23) that is provided on a subsequent stage side of the detector (5) and forms an image on the continuous paper (P); and a controller (101) that causes the image former (23) to start forming an image according to a position setting for forming an image on the continuous paper (P) using the image former (23) after a mark (M) on the continuous paper (P) is detected. The controller (101) adjusts the position setting on the basis of a start position determined according to an image formation state.