Fixing Device Curved Holding Portion Elastic Member

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Solution Overview

Problem

Existing fixing devices face challenges in using sheet-shaped members with uniform thickness as elastic members, leading to increased manufacturing costs compared to using non-uniform thickness members.

Innovation Solution

A fixing device design that includes a pressing section with a holding portion inside the belt, which has a shape following the outer peripheral shape of the fixing section and holds an elastic member. This design allows the elastic member to deform and adjust pressure by allowing partial deformation in the thickness direction, using a pressure adjusting surface with a curved shape and features like unevenness, slits, or holes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a sheet-shaped member with uniform thickness is used as an elastic member, then manufacturing cost is reduced, but pressure adjustment capability deteriorates

Engineering Contradiction:
Improvemanufacturing costVSAvoidpressure adjustment capability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The holding portion is designed with a curved surface shape that provides different geometric characteristics at different locations. This local geometric variation enables uniform pressure distribution across the fixing section while using a simple uniform-thickness elastic member, resolving the contradiction between manufacturing simplicity and pressure adjustment capability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The holding portion employs a curved surface shape instead of a flat surface. This curvature allows the elastic member to deform uniformly when pressed against the fixing section, achieving consistent pressure distribution and maintaining adaptability while using a simple uniform-thickness member that is easier to manufacture.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Device complexity

If the holding portion has a flat shape, then device complexity is reduced, but pressure adjustment precision deteriorates

Engineering Contradiction:
Improveholding portion structureVSAvoidpressure adjustment precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The holding portion uses a curved surface shape that is relatively simple to manufacture compared to complex multi-component structures. This curvature provides inherent pressure adjustment precision by ensuring uniform contact and deformation of the elastic member, achieving both low device complexity and high pressure adjustment precision.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Reliability

If the elastic member is pressed against the fixing section, then fixing performance is improved, but peelability of recording medium deteriorates

Engineering Contradiction:
Improvefixing performanceVSAvoidpeelability
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The curved surface shape of the holding portion ensures that only the necessary portion of the elastic member deforms when pressed against the fixing section. This controlled partial deformation achieves sufficient fixing performance while preventing excessive pressure that would harm peelability, thus resolving the contradiction between fixing performance and recording medium peelability.

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

Enables the use of sheet-shaped members with uniform thickness as elastic members, reducing manufacturing costs while allowing for precise adjustment of pressure to maintain fixing performance and improve peelability of recording media.

Implementation Method 1

the elastic member has a shape along the holding portion due to deformation in a state of not being pressed against the fixing section

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4530751A1Fixing device and image forming apparatus
Publication Date: 2025.04.02 FUJIFILM BUSINESS INNOVATION CORP
  • EP4530751A1 patent drawingFigure 1
  • EP4530751A1 patent drawingFigure 2
  • EP4530751A1 patent drawingFigure 3

AI summary

A fixing device includes: an endless belt; a fixing section that forms a fixing nip by being in contact with the belt; and a pressing section that is disposed inside of the belt, has a shape following an outer peripheral shape of the fixing section, includes a holding portion that holds an elastic member, and presses the belt against the fixing section. The elastic member has a shape along the holding portion due to deformation in a state of not being pressed against the fixing section.