Fixing Belt Guide Slope Reduces Oil Leakage

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Solution Overview

Problem

Existing fixing devices face challenges in preventing oil leakage from the inner to the outer peripheral surface of the fixing belt, especially when the belt passes by guide members, and in effectively correcting meandering of the belt.

Innovation Solution

The proposed fixing device includes a fixing belt, holding members, a pressing roller, an oil applicator, and guide members with sloping guiding surfaces that tilt outward, reducing oil leakage and correcting meandering by strategically positioning the guide members relative to the steering roller and rotator roller.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a guide member with a vertical guiding surface is used to guide the fixing belt, then the belt positioning is simplified, but oil leaks from the inner peripheral surface to the outer peripheral surface of the fixing belt

Engineering Contradiction:
Improveguide member structureVSAvoidoil leakage
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The guiding surface of the guide member is changed from a vertical surface to a sloped surface that tilts toward the outer side of the longitudinal direction of the holding member. This parameter change in the surface geometry prevents oil from leaking along the fixing belt by altering the flow path and utilizing gravity to keep oil on the inner peripheral surface.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If the guiding surface of the guide member is formed as a vertical surface, then the structure is simpler, but oil leakage occurs when the fixing belt passes by the guide member

Engineering Contradiction:
Improveguiding surface formationVSAvoidoil leakage to outer peripheral surface
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The guiding surface is designed with a specific slope angle rather than a vertical orientation. This parameter change in the surface geometry prevents oil from leaking along the fixing belt by altering the flow path and utilizing gravity to keep oil on the inner peripheral surface, while still maintaining manufacturability through standard machining processes.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If a steering roller is tilted to correct meandering of the fixing belt, then belt alignment is improved, but the complexity of the holding member increases

Engineering Contradiction:
Improvefixing belt alignmentVSAvoidholding member structure
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The steering roller is designed to automatically tilt in response to meandering of the fixing belt and then return to its original position. This self-correcting mechanism uses the belt's own movement to activate the correction, eliminating the need for external sensors or actuators, thereby improving alignment while minimizing added complexity.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4530752A1Fixing device and image forming apparatus
Publication Date: 2025.04.02 FUJIFILM BUSINESS INNOVATION CORP
  • EP4530752A1 patent drawingFigure 1
  • EP4530752A1 patent drawingFigure 2
  • EP4530752A1 patent drawingFigure 3A~3B

AI summary

A fixing device includes: a fixing belt; plural holding members that hold the fixing belt so that the fixing belt is rotatable; a pressing roller that presses the fixing belt against one of the plural holding members from an outer peripheral surface of the fixing belt so as to form a fixing processing portion; an applicator that applies oil to an inner peripheral surface of the fixing belt; and a first guide member that is provided for at least one holding member of the plural holding members and includes a guiding surface with which a side of the fixing belt is brought into contact, the guiding surface being formed as a slope tilting toward an outer side of a longitudinal direction of the at least one holding member.