Cartridge Positioning and Cleanerless Development System

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Solution Overview

Problem

Conventional image forming apparatuses with process cartridges require complex maintenance procedures and may experience issues with transfer residual developers adhering to charging rollers, affecting image quality and maintenance efficiency.

Innovation Solution

The development cartridge and drum cartridge configurations include a cleanerless system with an optical static-reducing member and a peripheral speed difference between the charging roller and photosensitive drum to prevent transfer residual developers from adhering to the charging roller, and a configuration where the developing roller collects and reuses residual developers, integrating a developing roller gear for synchronized rotation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional process cartridge system is used, then maintenance can be executed by a user without a service person, but transfer residual developers may adhere to charging rollers, affecting image quality

Engineering Contradiction:
Improvemaintenance executionVSAvoidtransfer residual developer adhesion
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful effect of transfer residual developers by introducing an optical static-reducing member that reduces the static charge of residual developers, preventing them from adhering to the charging roller. The peripheral speed difference between the charging roller and photosensitive drum also converts the potential harm into benefit by creating a speed differential that prevents adhesion while maintaining the cleanerless system's simplicity for user maintenance

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Object-affected harmful factors

If cleaning members are added to remove transfer residual developers, then image quality improves, but device complexity and maintenance requirements increase

Engineering Contradiction:
Improvetransfer residual developer adhesionVSAvoidcleaning member configuration
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent extracts the cleaning function from the traditional cleaning member configuration and replaces it with a cleanerless system. Instead of adding cleaning members that would increase device complexity, the invention removes the need for cleaning members entirely by using the optical static-reducing member and peripheral speed difference to prevent adhesion at its source

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system performs self-service by using the optical static-reducing member to automatically reduce static charge and prevent residual developer adhesion without requiring separate cleaning members or complex cleaning mechanisms. The peripheral speed difference between rollers also contributes to this self-service function by naturally preventing adhesion through speed differential

Inventive Principle:
Principle #25Self-service

3Loss of substance

If the developing roller collects and reuses residual developers, then material efficiency improves, but the system requires synchronized rotation control

Engineering Contradiction:
Improveresidual developer wasteVSAvoidsynchronized rotation control
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The patent merges the rotation control of the developing roller with the photosensitive drum by engaging a developing roller gear with the photosensitive drum gear. This integration allows the developing roller to rotate in synchronization with the photosensitive drum, enabling residual developer collection and reuse without requiring separate complex control mechanisms

Inventive Principle:
Principle #5Merging (Combining)

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 configuration enhances maintenance efficiency by eliminating the need for cleaning members and ensures consistent image quality by effectively managing transfer residual developers, reducing adhesion to the charging roller and utilizing residual developers within the system.

Implementation Method 1

an optical static-reducing member to prevent transfer residual developers from adhering to the charging roller

Methodology Applied
Scientific EffectElectrostatic reduction: Electrostatics

Implementation Method 2

a peripheral speed difference between the charging roller and photosensitive drum to prevent transfer residual developers from adhering to the charging roller

Methodology Applied
Scientific EffectSpeed differential effect:

Implementation Method 3

a configuration where the developing roller collects and reuses residual developers, integrating a developing roller gear for synchronized rotation

Methodology Applied
Scientific EffectMechanical collection:

Data Source

PatentEP3144740B1Cartridge and member used for cartridge
Publication Date: 2021.11.24 CANON KK
  • EP3144740B1 patent drawingFigure 1
  • EP3144740B1 patent drawingFigure 2
  • EP3144740B1 patent drawingFigure 3

AI summary

A development container (16) includes a positioning portion (34b, 46b) and a rotation stop portion (34c, 46c) engaged with and guided by a guide of an image forming apparatus, and a longitudinal positioning portion (34v), at one end in an axial direction of a developer carrying member (13). In a state where a cartridge (B1) is attached to the image forming apparatus, when a cross-sectional positioning range (Sc) is defined by using a width, having one end at a point at which the rotation stop portion contacts the guide and another end at a point at which the positioning portion contacts the guide in an attachment direction of the cartridge, and a height being a width of the guide at one of the points, the longitudinal positioning portion overlaps the cross-sectional positioning range in a longitudinal direction.