Fuser Belt Fixing Device Thermal Stability and Wear Reduction

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Solution Overview

Problem

Existing fixing devices in electrophotographic image forming apparatuses face challenges with prolonged warm-up times, thermal instability, and wear issues, particularly in high-speed applications, due to the use of belt-based and film-based fuser assemblies.

Innovation Solution

A fixing device incorporating a tubular belt holder with a rotatable, flexible fuser belt, a heater, a fuser pad, and a pressure member, where the belt holder is heated conductively to uniformly heat the fuser belt, and a mounting attachment ensures precise positioning and retention, addressing thermal efficiency and wear concerns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a belt-based fuser assembly is used, then the fixing device can handle high-speed applications, but the warm-up time is prolonged and thermal efficiency is reduced

Engineering Contradiction:
Improveprocessing speedVSAvoidwarm-up time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The belt-based fuser assembly is divided into modular components: a rotatable fuser belt, a stationary heater assembly, and a pressure roller. This segmentation allows the heater to remain stationary and pre-heated while only the belt and pressure roller need to rotate during operation, reducing warm-up time while maintaining high-speed processing capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stationary heater is pre-heated to operating temperature before the fuser belt rotates into position. This preliminary heating action eliminates the need to heat the entire belt assembly during warm-up, significantly reducing warm-up time while maintaining thermal efficiency during high-speed operation

Inventive Principle:
Principle #10Preliminary action

2Loss of time

If a film-based fuser assembly is used, then warm-up time is reduced and thermal efficiency is improved, but wear and friction increase

Engineering Contradiction:
Improvewarm-up timeVSAvoidwear resistance
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

A thin fuser belt made of flexible material is used instead of a thick belt or rigid film assembly. The thin belt has low thermal mass for rapid heating while the flexible material provides wear resistance and durability through repeated rotation and contact with the pressure roller

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The stationary heater assembly replaces the mechanically complex rotating heater found in traditional designs. This substitution eliminates mechanical wear on the heater components while maintaining reliable thermal contact through the flexible belt, improving overall system reliability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If a multi-roller belt fuser assembly is used, then fixing performance is improved, but device complexity increases

Engineering Contradiction:
Improvefixing performanceVSAvoidnumber of rollers
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The heater function is extracted from the rotating belt assembly and placed in a separate stationary heater unit. This extraction simplifies the rotating mechanism to only the belt and pressure roller while maintaining all necessary fixing functions through the combination of stationary heating and rotating pressing

Inventive Principle:
Principle #2Taking out (Extraction)

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

The solution reduces warm-up times, enhances thermal stability, and minimizes wear, enabling efficient high-speed operation with improved fusing performance and reduced energy consumption.

Implementation Method 1

the belt holder is heated conductively to uniformly heat the fuser belt

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2466389B1Belt assembly, fixing device, and image forming apparatus incorporating same
Publication Date: 2019.09.11 RICOH CO LTD
  • EP2466389B1 patent drawingFigure 1~2
  • EP2466389B1 patent drawingFigure 3
  • EP2466389B1 patent drawingFigure 4

AI summary

A fixing device includes a frame, a tubular belt holder, a rotatable, flexible fuser belt, a heater, a fuser pad, a pressure member, and a mounting attachment. The tubular belt holder extends in an axial direction thereof. The fuser belt is looped into a generally cylindrical configuration around the belt holder to rotate in a circumferential direction of the belt holder. The heater is disposed adjacent to the belt holder to heat the belt holder. The fuser pad is accommodated in the belt holder inside the loop of the fuser belt, and extends in the axial direction. The pressure member is disposed opposite the belt holder with the fuser belt interposed between the fuser pad and the pressure member. The mounting attachment is provided to a longitudinal end of the tubular belt holder to allow retention and detachable attachment of the belt holder end to the frame.