Photoreceptor Circulating Agent Applicator for Surface Stability

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Solution Overview

Problem

Existing image forming apparatuses using organic photoreceptors face challenges in maintaining the longevity of photoreceptors due to surface property changes, leading to abnormal images and frequent replacements, which results in high energy consumption and carbon dioxide emissions.

Innovation Solution

The image forming apparatus incorporates a circulating agent applicator that applies a circulating agent to the photoreceptor's base outermost layer, maintaining a balanced mass thickness and defect area to form a stable circulating outermost layer, preventing contamination and extending the photoreceptor's life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a crosslinked resin layer or sol-gel hardened layer is formed as the outermost layer of the photoreceptor, then mechanical strength and photosensitivity are improved, but the outermost layer becomes abradable after repeated use, leading to surface property changes and frequent replacements

Engineering Contradiction:
Improvemechanical strengthVSAvoidsurface stability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent changes the chemical structure parameter of the outermost layer from conventional crosslinked or sol-gel structures to a polyurethane structure with specific functional groups (isocyanate groups). This parameter change enables the layer to maintain mechanical strength while preventing abrasion and surface property changes during repeated use, resolving the contradiction between strength and surface stability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite structure where a polyurethane outermost layer containing isocyanate groups is combined with the photoreceptor's charge transport material. This composite material approach allows the outermost layer to provide both mechanical protection and chemical stability, preventing the abrasion problems of conventional single-material structures.

Inventive Principle:
Principle #40Composite materials

2Productivity

If the photoreceptor is used repeatedly, then productivity is improved, but surface properties change causing abnormal images and deteriorated cleaning property, requiring frequent replacements

Engineering Contradiction:
Improveusage durationVSAvoidimage quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies a preliminary protective action by forming a polyurethane outermost layer with isocyanate groups before the photoreceptor enters service. This pre-formed protective layer prevents surface property changes during repeated use, ensuring image quality remains stable throughout the photoreceptor's operational life and eliminating the need for frequent replacements.

Inventive Principle:
Principle #10Preliminary action

3Loss of energy

If the photoreceptor life is extended, then energy consumption and carbon emissions are reduced, but conventional outermost layer structures become abradable and unstable

Engineering Contradiction:
Improveenergy consumptionVSAvoidsurface stability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent changes the chemical composition parameter of the outermost layer to a polyurethane structure with isocyanate groups, which fundamentally alters the layer's properties. This parameter change enables the layer to resist abrasion and maintain surface stability over extended periods, allowing the photoreceptor to be used repeatedly without frequent replacements, thereby reducing energy consumption and carbon emissions.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2755089B1Image forming apparatus, and image forming method
Publication Date: 2016.11.02 RICOH CO LTD
  • EP2755089B1 patent drawingFigure 1~2
  • EP2755089B1 patent drawingFigure 3
  • EP2755089B1 patent drawingFigure 4

AI summary

An image forming apparatus is provided. The image forming apparatus includes a photoreceptor (11); a charger (12) to charge a surface of the photoreceptor; a circulating agent applicator (3) to apply a circulating agent to the surface of the photoreceptor while contacting the surface of the photoreceptor to form a film of the circulating agent on the surface of the photoreceptor; and a contact member (3C; 17) contacted with the surface of the photoreceptor. The acting force, which is generated by contact of the contact member with the photoreceptor and includes a tangential force Ft, which is a force in a tangential direction at a contact portion of the contact member with the surface of the photoreceptor, and a normal force Fn, which is a force in a normal direction at the contact portion, satisfies the following relationships, 0.90 ≤ Ft/Fn ≤ 0.96, and 1.15kgf ≤ Ft ≤ 1.35kgf.