Separating Member with Variable Thickness for Fixing Belt

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Solution Overview

Problem

Conventional fixing devices face challenges in maintaining uniform separation gaps between the fixing belt and the separating member, leading to potential paper jam and damage to the fixing belt, especially during high-speed operations and varying paper widths.

Innovation Solution

The design incorporates a separating member with a receding and approaching portion at its leading end, allowing for a varying thickness in the axial direction to match the shape of the fixing belt, ensuring a uniform separation gap and preventing jamming and belt damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the separating member has a uniform thickness, then the structure is simple and easy to manufacture, but the separation gap becomes non-uniform during high-speed rotation causing paper jam and belt damage

Engineering Contradiction:

Improveease of manufactureVSAvoidseparation reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The separating member is designed with non-uniform thickness, where the leading end portion has a smaller thickness than the rear end portion. This local variation in thickness compensates for the radial displacement of the fixing belt during high-speed rotation, maintaining a uniform separation gap throughout the rotation cycle and preventing paper jam and belt damage.

Inventive Principle:

Principle #3Local quality

2Productivity

If the fixing belt rotates at high speed to increase productivity, then the printing speed increases, but the separation gap becomes non-uniform causing paper jam and belt damage

Engineering Contradiction:

ImproveproductivityVSAvoidseparation reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The separating member features a leading end portion with reduced thickness compared to the rear end portion. This local thickness variation is specifically designed to compensate for the radial displacement of the fixing belt that occurs during high-speed rotation, ensuring uniform separation gap maintenance and reliable paper separation even at high productivity speeds.

Inventive Principle:

Principle #3Local quality

3Reliability

If the separation gap is reduced to prevent paper jam, then separation reliability improves, but the risk of belt damage increases during high-speed operation

Engineering Contradiction:

Improveseparation reliabilityVSAvoidbelt damage risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The separating member is designed with a leading end portion having smaller thickness than the rear end portion. This local thickness reduction creates an optimal separation gap that prevents paper jam while avoiding contact with the fixing belt during high-speed rotation, thereby eliminating belt damage risk.

Inventive Principle:

Principle #3Local quality

4Productivity

If the separating member is positioned closer to the fixing belt to improve separation, then separation efficiency increases, but the uniformity of separation gap during rotation decreases

Engineering Contradiction:

Improveseparation efficiencyVSAvoidseparation gap uniformity

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The separating member features a leading end portion with reduced thickness compared to the rear end portion. This local thickness variation allows the separating member to be positioned optimally close to the fixing belt for efficient separation while compensating for radial displacement during rotation, maintaining uniform separation gap throughout the rotation cycle.

Inventive Principle:

Principle #3Local quality

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 stabilizes the separation property, preventing paper jam and belt damage, even at varying rotation speeds and paper widths, by uniformly maintaining the separation gap and enhancing the overall performance of the fixing device.

Implementation Method 1

a heat source heating the fixing belt

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 2

a separating member that extends near the nip portion and separates a recording medium from a surface of the fixing belt

Methodology Applied

Scientific EffectMechanical separation:

Implementation Method 3

an opposing rotator forming a nip portion between the opposing rotator and the fixing belt by abutting onto the nip forming member via the fixing belt

Methodology Applied

Scientific EffectMechanical pressure:

Data Source

PatentUS9063480B2Fixing device, image forming device, and separating member

Publication Date: 2015.06.23 RICOH CO LTD

AI summary

In an embodiment, provided is a fixing device that includes: a fixing belt rotatable and endless; a belt holding member holding the fixing belt at each end part in an axial direction; a heat source heating the fixing belt; a nip forming member provided inside the fixing belt; an opposing rotator forming a nip portion between the opposing rotator and the fixing belt via the fixing belt; and a separating member that extends near the nip portion and separates a recording medium from a surface of the fixing belt. A leading end of the separating member is provided with a receding portion and an approaching portion that is at a different position from a position of the receding portion different in the axial direction. The approaching portion is provided nearer to the nip portion than the receding portion is provided.