Fixing Belt Rotation Detection via Inner Surface Contact

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional fixing devices with a slide belt mechanism face issues with wear and decreased durability due to increased sliding load and surface deterioration, leading to potential slip between the fixing belt and pressuring member, which complicates rotation detection and may cause local heating and deformation of the fixing belt.

Innovation Solution

The fixing device incorporates a detecting mechanism with cap members and elastic members that rotate with the fixing belt, allowing for reliable rotation detection and preventing local heating by adjusting the contact points and using an induction heating unit to maintain efficient belt operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a roller of the rotation detecting part comes into contact with the outer circumference face of the fixing belt to detect rotation, then the rotation state of the fixing belt can be detected, but paper dust, toner, and lubricant spread to the contact surface causing slip between the fixing belt and roller, making rotation detection unreliable

Engineering Contradiction:
Improverotation detection accuracyVSAvoidrotation detection reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces a detection roller that contacts the inner circumference face of the fixing belt through the elastic member, rather than directly contacting the outer circumference face. This intermediary contact point avoids contamination from paper dust, toner, and lubricant that accumulate on the outer surface, ensuring reliable rotation detection throughout the fixing belt's operational life.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If a roller comes into contact with the outer circumference face of the fixing belt for rotation detection, then rotation can be detected, but stress concentrates on the contact portion causing durability deterioration of the fixing belt

Engineering Contradiction:
Improverotation detection capabilityVSAvoidfixing belt durability
Core Design Contradiction:
Measurement precisionVSDuration of action of stationary object

Solution Approach 1:

The patent inverts the conventional approach by having the detection roller contact the inner circumference face of the fixing belt instead of the outer circumference face. This reversal moves the detection contact point to a location that does not concentrate stress on the outer surface, thereby preventing durability deterioration while maintaining rotation detection capability.

Inventive Principle:
Principle #13The other way round (Inversion)

3Use of energy by stationary object

If the fixing device uses a slide belt manner with flexible fixing belt and pressuring member, then heat capacity is reduced and energy saving is achieved, but wear increases and sliding load increases leading to potential slip and local heating

Engineering Contradiction:
Improveenergy efficiencyVSAvoidfixing operation reliability
Core Design Contradiction:
Use of energy by stationary objectVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the rotation detection part continuously monitors the rotation state of the fixing belt. When slip is detected between the pressuring member and fixing belt, the system can respond by adjusting operational parameters or alerting operators, preventing the progression to local heating and deformation, thus maintaining fixing operation reliability despite the slide belt design.

Inventive Principle:
Principle #23Feedback

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 ensures reliable rotation detection and prevents local heating of the fixing belt, maintaining its integrity and improving the durability of the fixing device while reducing heat capacity and enhancing energy efficiency.

Implementation Method 1

an induction heating unit to maintain efficient belt operation

Methodology Applied
Scientific EffectInduction heating: Induction Heating

Data Source

PatentEP2889698B1Fixing device and image forming apparatus
Publication Date: 2018.05.09 KYOCERA DOCUMENT SOLUTIONS INC
  • EP2889698B1 patent drawingFigure 1
  • EP2889698B1 patent drawingFigure 2
  • EP2889698B1 patent drawingFigure 3

AI summary

A fixing device (18) includes a fixing belt (21), a pressuring member (22), a pressing member (25), a guiding member (27), a cap member (28), an elastic member (29, 61) and a detecting mechanism (30). The pressing member (25) includes a pressing face (46) pressing the fixing belt (21) to a side of the pressuring member (22). The fixing belt (21) includes a bulging part (21c) arranged at the downstream side from a fixing nip (32) in a conveying direction. The cap member (28) includes a facing part (48a) facing to the bulging part (21c). Before the pressuring member (22) comes into pressure contact with the fixing belt (21), a gap (G) is arranged between the bulging part (21c) and facing part (48a). When the pressuring member (22) comes into pressure contact with the fixing belt (21), the bulging part (21c) bulges toward an external diameter side of the fixing belt (21) to fill up the gap (G) and the cap member (28) is held by an end part (21a, 21b) of the fixing belt (21) via the elastic member (29, 61).