Fuser Unit Belt Guide Integrating Restraint and Inner Surface Guidance

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Solution Overview

Problem

Existing fuser units for electrophotographic image forming apparatuses face challenges in maintaining the size and stability of the fuser unit, particularly in guiding and restraining the endless belt, leading to potential enlargement and deflection issues.

Innovation Solution

The fuser unit incorporates a belt guide with a restraining part and an inner surface guide that is urged by a spring towards the inner circumferential surface of the endless belt, ensuring proper tension and alignment, and is designed to minimize the size of the fuser unit by integrating the restraining part with the inner surface guide, allowing for stable belt circulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separate restraining part and inner surface guide are provided, then the belt guidance function is improved, but the device size increases

Engineering Contradiction:

Improvebelt guidance functionVSAvoidfuser unit size

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The restraining part and inner surface guide are merged into a single integrated belt guide structure. The belt guide includes both the restraining part that contacts the end surface of the belt and the inner surface guide that extends into the belt to guide its inner circumferential surface, combining multiple guidance functions into one component to reduce overall device size.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The belt guide serves multiple functions simultaneously: it restrains the belt from moving in the first direction through the restraining part, guides the inner circumferential surface of the belt through the inner surface guide, and maintains proper belt tension through the urging member. This multi-functional design reduces the need for separate components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Ease of operation

If the inner surface guide is positioned away from the belt, then the belt can move freely, but belt stability and tension control deteriorate

Engineering Contradiction:

Improvebelt movement freedomVSAvoidbelt stability

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

The belt guide is designed to be movable in the direction of stretching the belt through the urging member (spring). This allows the belt guide to dynamically adjust its position to maintain optimal contact with the belt, ensuring both freedom of movement and stable tension control. The spring enables the guide to follow belt tension variations while maintaining guidance.

Inventive Principle:

Principle #15Dynamics

3Reliability

If multiple separate components are used for belt guidance, then each component can be optimized, but the device complexity increases

Engineering Contradiction:

Improvebelt guidance precisionVSAvoidnumber of components

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

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

This configuration effectively suppresses the enlargement of the fuser unit, maintains belt stability, and ensures secure guidance of the endless belt, preventing deflection and ensuring consistent operation.

Implementation Method 1

an urging member, which is configured to urge the belt guide in an urging direction so that the inner surface guide is urged toward the inner circumferential surface of the endless belt

Methodology Applied

Scientific EffectElastic force: Elasticity

Implementation Method 2

a restraining part, which is configured to restrain the endless belt from moving in the first direction

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS9690241B2Belt guide for fuser unit

Publication Date: 2017.06.27 BROTHER KOGYO KK

AI summary

A fuser unit includes: an endless belt, which has an end portion having an end surface in a first direction; a nip member, which extends in the first direction and is arranged inside the endless belt; a belt guide, which is arranged to be in contact with the end surface of the endless belt and includes: a restraining part, which is configured to restrain the endless belt from moving in the first direction; and an inner surface guide, which extends from the restraining part into an inside of the endless belt and guides the inner circumferential surface of the endless belt; and an urging member, which is configured to urge the belt guide in a urging direction so that the inner surface guide is urged toward the inner circumferential surface of the endless belt.