Segmented Cleaning Blade for Electrophotographic Photoreceptors

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Solution Overview

Problem

Conventional cleaning blades in electrophotographic image forming apparatuses suffer from reduced cleaning ability due to deformation, leading to low contact pressure and ineffective removal of residual toner, especially when used with photoreceptors coated with protective agents or toners containing lubricants like zinc stearate, resulting in defective image quality.

Innovation Solution

A cleaning blade with a layered structure, where the edge layer has a higher hardness than the backup layer, ensuring consistent contact pressure and preventing plastic deformation, thereby maintaining effective cleaning performance over time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional cleaning blade with uniform hardness is used, then the blade can be manufactured simply, but the blade deforms after long use resulting in reduced contact pressure and cleaning ability

Engineering Contradiction:

Improvecleaning abilityVSAvoidblade structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The cleaning blade is divided into multiple layers with different hardness values. The edge layer has higher hardness to resist deformation and maintain cleaning ability, while the backup layer has lower hardness to provide flexibility and absorb stress. This segmentation resolves the contradiction by allowing each layer to perform its specific function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The cleaning blade uses a composite structure combining materials of different hardness values in specific layers. The edge layer uses harder material to prevent deformation, while the backup layer uses softer material for flexibility. This composite approach maintains simple manufacturing while significantly improving reliability and cleaning performance over time.

Inventive Principle:

Principle #40Composite materials

2Reliability

If the cleaning blade edge is made harder to prevent deformation, then the cleaning ability is improved, but the blade causes more damage to the photoreceptor surface

Engineering Contradiction:

Improvecleaning abilityVSAvoidphotoreceptor surface damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The cleaning blade applies local quality by making only the edge layer hard while keeping the backup layer soft. This allows the edge to effectively clean the photoreceptor surface without the entire blade being hard enough to cause damage. The localized hardness distribution resolves the contradiction between cleaning effectiveness and surface protection.

Inventive Principle:

Principle #3Local quality

3Object-affected harmful factors

If the cleaning blade is made softer to protect the photoreceptor, then surface damage is reduced, but the blade deforms quickly and loses cleaning effectiveness

Engineering Contradiction:

Improvephotoreceptor surface damageVSAvoidcleaning ability

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The blade is segmented into edge and backup layers with different hardness properties. The edge layer maintains hardness for effective cleaning, while the backup layer provides softness for photoreceptor protection and flexibility. This segmentation resolves the contradiction by distributing different functional requirements to different layers.

Inventive Principle:

Principle #1Segmentation

4Ease of manufacture

If a single-layer cleaning blade is used, then manufacturing is simpler, but the blade cannot maintain consistent contact pressure over time

Engineering Contradiction:

Improveblade manufacturingVSAvoidcontact pressure consistency

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The cleaning blade uses a composite multi-layer structure where each layer contributes specific properties. The edge layer provides hardness for consistent contact pressure, while the backup layer provides flexibility and stress absorption. This composite structure maintains manufacturability while significantly improving contact pressure consistency over time.

Inventive Principle:

Principle #40Composite materials

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 cleaning blade maintains high contact pressure and effective cleaning performance even after long use, preventing toner and protective agents from passing through the nip, thus enhancing image quality by reducing defects like white omissions and vertical streaks.

Implementation Method 1

The cleaning blade 200 rubs the surface of the photoreceptor 210 with the edge thereof to peel residual toner adhered to the surface of the photoreceptor

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS9081353B2Cleaner, and process cartridge and image forming apparatus using the cleaner

Publication Date: 2015.07.14 RICOH CO LTD

AI summary

A cleaner is provided. The cleaner includes a cleaning blade having an edge to be contacted with a surface of a member to be cleaned while moving relative to the member to clean the surface of the member. The cleaning blade includes the edge, and first and second side surfaces, wherein the edge is disposed between the first and second side surfaces. When the cleaning blade is not contacted with the surface of the member to be cleaned, the first side surface is opposed to the surface of the member, and when the cleaning blade is contacted with the surface of the member, the edge, and the first and second side surfaces of the cleaning blade are contacted with the surface of the member.