Lubricant Application Blade Hardness for Image Bearer Protection

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Solution Overview

Problem

Existing image bearer protection and cleaning technologies in electrophotography lead to increased consumption of protective agents, abrasion of cleaning blades, and frequent maintenance, causing environmental impact and performance issues.

Innovation Solution

A protective layer forming device using a lubricant application blade with a polyurethane elastomer contact portion having a specific Martens hardness range, applying a lubricant with controlled ionic strength, to form a protective layer that enhances image bearer protection and cleaning performance over time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a protective agent containing fatty acid metal salt and boron nitride is used to protect the image bearer, then image bearer protection performance is improved, but protective agent consumption increases and maintenance frequency increases

Engineering Contradiction:
Improveimage bearer protection performanceVSAvoidprotective agent consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent changes the particle size parameters of boron nitride (secondary particle diameter: 3.0-14.0 μm, crystal particle diameter: 0.1-1.0 μm) and compositional parameters (fatty acid metal salt content, boron nitride content) to optimize the protective agent formulation, reducing consumption while maintaining protection performance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite material system combining fatty acid metal salt and boron nitride with specific particle size distribution, creating a synergistic effect that improves protection performance while reducing the total amount of protective agent needed

Inventive Principle:
Principle #40Composite materials

2Reliability

If a protective agent containing fatty acid metal salt and boron nitride is used to protect the image bearer, then image bearer protection performance is improved, but cleaning blade abrasion increases and maintenance frequency increases

Engineering Contradiction:
Improveimage bearer protection performanceVSAvoidcleaning blade service life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent optimizes the particle size parameters of boron nitride and compositional ratios to create a protective agent that is gentler on cleaning blades, extending their service life while maintaining image bearer protection

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a protective agent containing fatty acid metal salt and boron nitride is used to protect the image bearer, then image bearer protection performance is improved, but application blade abrasion increases and maintenance frequency increases

Engineering Contradiction:
Improveimage bearer protection performanceVSAvoidapplication blade service life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent adjusts the particle size and composition parameters of the protective agent to reduce abrasiveness against application blades, extending their service life while maintaining effective protective layer formation

Inventive Principle:
Principle #35Parameter changes

4Reliability

If a rubber blade cleaner is used to remove residual toner particles, then cleaning performance is improved, but image bearer wear and scratches increase

Engineering Contradiction:
Improvecleaning performanceVSAvoidimage bearer wear and scratches
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a protective layer as an intermediary between the image bearer and cleaning components. This protective layer acts as a sacrificial element that reduces direct contact and friction between the rubber blade cleaner and the image bearer surface, thereby reducing wear and scratches while maintaining cleaning effectiveness

Inventive Principle:
Principle #24Intermediary (Mediator)

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 stabilizes the lubricant application, reduces wear on the blade, prevents abnormal images, and maintains image quality, thereby extending the lifespan of the image bearer and reducing maintenance frequency.

Implementation Method 1

The contact portion has a Martens hardness of 5.0 N/mm 2 where the normalized ionic strength A is measured by a time-of-flight secondary ion mass spectrometer

Methodology Applied
Scientific EffectMartens hardness:

Implementation Method 2

The lubricant includes fatty acid metal salt

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP4664205A1Protective layer forming device and image forming apparatus
Publication Date: 2025.12.17 RICOH CO LTD
  • EP4664205A1 patent drawingFigure 1~2
  • EP4664205A1 patent drawingFigure 3
  • EP4664205A1 patent drawingFigure 4

AI summary

A protective layer forming device (10) includes lubricant (103) including fatty acid metal salt and a lubricant application blade (104). The lubricant application blade (104) includes a contact portion (602) contacting a surface of an image bearer (3) to apply the lubricant on the surface of the image bearer. The contact portion (602) includes polyurethane elastomer that includes a reaction product of polytetramethylene ether glycol, aromatic isocyanate, and amine. The contact portion (602) has a Martens hardness of 5.0 N/mm2 or more and 30.0 N/mm2 or less. The lubricant (103) applied to the surface of the image bearer (3) by the lubricant application blade (104) has a normalized ionic strength A of a metal ion amount derived from the fatty acid metal salt, satisfying a following expression (1), 1E−4<A<20E−4 where the normalized ionic strength A is measured by a time-of-flight secondary ion mass spectrometer.