Airflow Suppressing Member in Fixing Roller Gap

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Solution Overview

Problem

The existing image forming apparatuses face challenges in reducing the number of ultrafine particles of parting wax discharged outside, which leads to image loss and contamination due to insufficient or excessive heating during the fixing process.

Innovation Solution

The implementation of an airflow suppressing member in the gap region between the film and the pressing roller core metal, which reduces airflow and thereby minimizes the discharge of ultrafine particles by agglomerating them within the device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the film temperature is excessively high, then melting of the toner is sufficient, but a viscosity of the toner is lowered, so that a part of the melted toner is peeled off from the recording material to contaminate the film surface

Engineering Contradiction:
Improvefilm temperatureVSAvoidtoner contamination on film surface
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

The patent introduces an airflow suppressing member that changes the airflow parameters in the gap region, reducing air flow velocity and direction to prevent toner particles from being carried onto the film surface, thereby resolving the contamination issue while maintaining high temperature fixing

Inventive Principle:
Principle #35Parameter changes

2Shape

If a gap is created between the film and the core metal protruded from the elastic layer and the parting layer of the pressing roller, then protrusion of the pressing roller from an end surface of the film is prevented, but airflow is generated in the fixing device when the recording material is fed, thus strengthen the action of pushing out the air in the fixing device together with the recording material to an outside of the printer

Engineering Contradiction:
Improvegap structureVSAvoidairflow discharge of ultrafine particles
Core Design Contradiction:
ShapeVSObject-generated harmful factors

Solution Approach 1:

The airflow suppressing member acts as an intermediary element in the gap region, mediating between the necessary gap structure and the harmful airflow. It blocks and redirects airflow to prevent ultrafine particles from being discharged outside while maintaining the structural benefits of the gap

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If the number of ultrafine particles discharged outside is reduced, then image loss and contamination are prevented, but the particles must be maintained within the apparatus

Engineering Contradiction:
Improveultrafine particles dischargeVSAvoidparticle containment structure
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The invention extracts the airflow control function from the overall fixing device structure by introducing a dedicated airflow suppressing member. This localized solution addresses the particle discharge problem without requiring complex system-wide modifications, achieving effective particle containment with minimal added complexity

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

This solution effectively decreases the number of ultrafine particles discharged outside, enhancing the fixing process by maintaining the particles within the apparatus, thus preventing image loss and contamination.

Implementation Method 1

a heater including a ceramic substrate and a heat generating resistor formed on the substrate

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

the parting wax contained in the toner image is liquefied by simultaneous heating and pressing

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

a part of the parting wax is vaporized to be placed in a vaporized state. The vaporized component of the parting wax floats in the air in the fixing device in the form of airborne small diameter particles

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 4

airflow is generated in the fixing device when the recording material is fed, thus strengthen the action of pushing out the air in the fixing device together with the recording material to an outside of the printer

Methodology Applied
Scientific EffectAirflow: Convection

Implementation Method 5

an airflow suppressing member in the gap region between the film and the pressing roller core metal, which reduces airflow and thereby minimizes the discharge of ultrafine particles by agglomerating them within the device

Methodology Applied
Scientific EffectAirflow suppression: Convection

Data Source

PatentEP2793085B1Image forming apparatus
Publication Date: 2022.06.22 CANON KK
  • EP2793085B1 patent drawingFigure 1
  • EP2793085B1 patent drawingFigure 2(a)~2(c)
  • EP2793085B1 patent drawingFigure 3(a)~3(c)

AI summary

An image forming apparatus includes an image forming portion; and a fixing portion. The fixing portion includes a cylindrical film, a nip-forming member and a roller including a shaft portion and an elastic layer. The elastic layer contacts an outer surface of the film except an end region of the film with respect to a generatrix direction. In the end region, the shaft portion and the outer surface of the film oppose each other with a spatial region with respect to a radial direction of the shaft portion. The image forming apparatus includes a spacer occupying at least a part of the spatial region.