Fixing Member Elastic Layer for Image Quality

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Solution Overview

Problem

Existing fixing members in electrophotographic color image forming apparatuses face challenges in releasing recording media without jamming and maintaining image quality due to insufficient responsiveness to surface irregularities of the recording medium, while also requiring durability, which is compromised by softer rubber materials used to improve responsiveness.

Innovation Solution

A fixing member with an elastic layer containing a polymer derived from terpene and having a main chain with a silicon atom, providing improved responsiveness to surface irregularities without compromising the durability of the rubber, achieved by mixing the polymer with terpene and applying it to a heat-resistant base.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If silicone rubber is used to form the elastic layer, then the releasing property is improved, but the responsiveness to surface irregularities deteriorates

Engineering Contradiction:
Improvereleasing propertyVSAvoidresponsiveness to surface irregularities
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The elastic layer is formed as a composite material comprising fluororesin and silicone rubber in a specific weight ratio range (fluororesin: 1-40 wt%, silicone rubber: 60-99 wt%). This composite structure combines the excellent releasing properties of fluororesin with the superior responsiveness to surface irregularities of silicone rubber, resolving the contradiction between these two opposing requirements.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If a rubber with low hardness is used to improve responsiveness, then the responsiveness to irregularities is improved, but the durability deteriorates

Engineering Contradiction:
Improveresponsiveness to irregularitiesVSAvoiddurability
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The hardness of the elastic layer is controlled within a specific range of 30-80 degrees Shore A by adjusting the composition ratio of fluororesin and silicone rubber. This parameter optimization ensures that the rubber maintains sufficient softness for responsiveness while preserving adequate hardness for durability, preventing the deterioration associated with overly soft materials.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If fluororesin is used as the outermost surface to improve releasing property, then the releasing property is improved, but the image quality uniformity deteriorates

Engineering Contradiction:
Improvereleasing propertyVSAvoidimage quality uniformity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The elastic layer exhibits local quality differentiation through its composite structure where fluororesin provides releasing properties at the molecular level while silicone rubber dominates the macroscopic mechanical behavior. This localized functional distribution allows the surface to maintain excellent releasing properties while the bulk material provides the responsiveness needed for uniform image quality.

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

The solution enables the production of high-quality images without unevenness over a long period, maintaining the durability of the rubber while enhancing the fixing member's ability to handle surface irregularities, thus preventing jamming and ensuring consistent image output.

Implementation Method 1

an elastic layer provided on the base, wherein the elastic layer contains a polymer having a structure derived from terpene and a structure where the main chain contains a silicon atom

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a fixing member configured to heat and fix the toner on the recording medium

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

a press member that forms a nip with the fixing member. When the recording medium is passed through the nip, the toner is heated and pressurized so that the toner is fixed onto the recording medium

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP2834711B1Fixing member for image forming apparatus, fixing device, and image forming apparatus
Publication Date: 2019.05.08 RICOH CO LTD
  • EP2834711B1 patent drawingFigure 1~2
  • EP2834711B1 patent drawingFigure 3~4
  • EP2834711B1 patent drawing

AI summary

To provide an elastic member for image forming apparatus, which contains: a base; and an elastic layer provided on the base, wherein the elastic layer contains a polymer having a structure derived from terpene and a structure where a main chain contains a silicon atom.