Developing Apparatus Seal with Low-Friction Region

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Solution Overview

Problem

Conventional developing apparatuses experience toner leakage and abnormal image formation due to frictional heat generated between the toner bearing member and seals, leading to toner melting and scattering, and the presence of impurities from these sliding parts inhibiting normal image formation.

Innovation Solution

A developing apparatus with a seal that includes a low-friction region with a fluorine-based resin on at least part of its contact surface with the toner bearing member, reducing frictional resistance and preventing toner leakage, and a circumferential surface arrangement to prevent deposits from reaching the image forming region.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a seal contacts the toner bearing member to prevent toner leakage, then toner leakage is prevented, but frictional heat is generated causing toner melting and abnormal image formation

Engineering Contradiction:

Improvetoner leakage preventionVSAvoidfrictional heat

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The seal material is changed from conventional materials to PTFE (polytetrafluoroethylene), which has fundamentally different friction characteristics. This parameter change in material composition reduces the friction coefficient dramatically, thereby reducing frictional heat generation while maintaining the sealing function that prevents toner leakage.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The seal is constructed as a composite structure with a PTFE layer formed on the contact surface with the toner bearing member. This composite material approach combines the sealing capability of the base seal material with the low-friction properties of PTFE, achieving both toner leakage prevention and reduced frictional heat.

Inventive Principle:

Principle #40Composite materials

2Reliability

If a seal contacts the toner bearing member to block the space, then toner leakage is prevented, but impurities are generated that inhibit normal image formation

Engineering Contradiction:

Improvespace blockingVSAvoidimpurities

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The material parameter of the seal is changed to PTFE, which has superior non-stick and low-friction properties. This parameter change prevents the generation of impurities through reduced friction and prevents toner adhesion to the seal surface, thereby eliminating the source of impurities that would otherwise inhibit normal image formation.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If the regulating member contacts the toner bearing member to regulate toner amount, then toner amount is controlled, but frictional heat melts toner and causes scattering

Engineering Contradiction:

Improvetoner amount controlVSAvoidfrictional heat

Core Design Contradiction:

Manufacturing precisionVSTemperature

Solution Approach 1:

The seal material is changed to PTFE with fundamentally different friction parameters. This parameter change reduces the friction coefficient at the contact interface between the seal and toner bearing member, thereby reducing frictional heat generation while maintaining the regulating function that controls toner amount.

Inventive Principle:

Principle #35Parameter changes

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 effectively reduces frictional heat, prevents toner leakage, and avoids abnormal image formation by minimizing frictional resistance and containing deposits outside the image forming region, thus ensuring consistent image quality.

Implementation Method 1

the contact portion includes a low-friction region with a fluorine-based resin on at least a part of a contact surface with the roller portion, the low-friction region having frictional resistance lower than frictional resistance without the fluorine-based resin

Methodology Applied

Scientific EffectFriction reduction by fluorine-based resin: Lubrication

Data Source

PatentUS8942590B2Developing apparatus, image forming apparatus and process cartridge

Publication Date: 2015.01.27 RICOH CO LTD

AI summary

A developing apparatus, including: a developer container; a toner bearing member including a roller portion; a seal; a regulating member; and a development entrance sealing member,wherein the seal includes a contact portion which contacts the roller portion,wherein the contact portion includes a low-friction region including a material on at least a part of a contact surface with the roller portion, wherein the low-frictional region including the material has frictional resistance between the contact surface and the roller portion lower than frictional resistance between the contact portion without the material and the roller portion, and the material reduces the frictional resistance at the contact surface, andwherein a circumferential surface of the roller portion contacting the low-friction region is arranged to face outward in a longitudinal direction of the photoconductor from a contact region of the cleaning unit with the photoconductor.