Fixing Roller Dynamics for Continuous Paper Thermal Control

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Solution Overview

Problem

Conventional image forming apparatuses using continuous paper face challenges in preventing thermal alteration, such as burning, due to prolonged stops in paper conveyance, as the fixing device continues to heat the paper, limiting the distance the fixing roller can be separated from the paper and thus unable to fully prevent heat transfer.

Innovation Solution

An image forming apparatus with a control unit that manages the conveyance of continuous paper to prevent a formed-image-free portion from staying in the fixing unit for a predetermined time, including periodic conveyance, temperature adjustments, and direction changes, ensuring the fixing unit's roller releases pressure and heats are managed after image formation stops.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the fixing roller is separated from the continuous paper while conveyance is stopped, then heat transfer to the paper is reduced, but the separation distance is limited due to lack of space, so thermal alteration cannot be fully prevented during extended stops

Engineering Contradiction:

Improvethermal alterationVSAvoidfixing device installation space

Core Design Contradiction:

Object-affected harmful factorsVSArea of stationary object

Solution Approach 1:

The fixing roller is designed to dynamically change its position relative to the continuous paper. During image forming operations, the roller maintains contact with the paper for fixing. During stopped periods exceeding a threshold duration, the roller automatically moves to a separated position away from the paper, and rotates in place to dissipate heat, preventing thermal alteration while adapting to space constraints

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the fixing roller based on the state of image forming operations. When operations stop for extended periods, the roller's position parameter changes from contact to separated, and its rotational state changes from fixed-position pressing to rotation in separated position, allowing heat dissipation without requiring large installation space

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If the fixing roller remains in contact with the continuous paper during stopped operations, then the fixing device structure is simple, but heat concentrates on local parts of the paper causing burn and thermal alteration

Engineering Contradiction:

Improvefixing device structureVSAvoidthermal alteration

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The fixing roller implements dynamic positional adjustment based on operational state. During active image forming, it maintains contact with the paper for proper fixing function. During extended stops, it moves to a separated position and rotates, preventing heat concentration while maintaining a relatively simple overall device structure without requiring complex mechanisms

Inventive Principle:

Principle #15Dynamics

3Object-affected harmful factors

If the fixing roller is separated from the continuous paper during stopped operations, then heat transfer is reduced, but the roller must be rotated in a state with no abutment to dissipate heat, adding operational complexity

Engineering Contradiction:

Improvethermal alterationVSAvoidroller operation control

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The fixing roller automatically performs heat dissipation rotation when separated from the paper during extended stops. The system controller monitors the stop duration and automatically commands the roller to rotate in the separated position, eliminating the need for manual intervention and simplifying overall operation while effectively preventing thermal alteration

Inventive Principle:

Principle #25Self-service

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 local thermal alteration of the continuous paper by ensuring the paper is not exposed to excessive heat, reducing the risk of burning and maintaining paper quality during extended stops.

Implementation Method 1

the fixing unit configured to fix by heat the image which has been formed on the continuous paper

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 2

heat is concentrated on a local part of the continuous paper, and thermal alteration, such as burn, may be generated

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS9869958B2Image forming apparatus that controls movement of a continuous sheet through a fixing unit

Publication Date: 2018.01.16 KONICA MINOLTA INC

AI summary

An image forming apparatus of the present invention includes: an image forming unit for forming an image on a continuous paper; a fixing unit for fixing by heat the image which has been formed on the continuous paper by the image forming unit; conveyance units for conveying the continuous paper; and a control unit for controlling the conveyance units to convey the continuous paper in such a manner that, when an image forming operation by the image forming unit is stopped, the same portion of the continuous paper, on which the image is not formed, does not remain in the fixing unit for a predetermined period of time.