Developing Unit Side Seal Toner Leakage Prevention

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Solution Overview

Problem

Existing developing units experience toner leakage due to non-unidirectional fibers in felt members, causing developer to be diverted away from the supply port during sliding contact with the developing roller.

Innovation Solution

A side sealing member with an upstream side seal and a downstream side seal is implemented, where the upstream side seal conveys toner obliquely towards the supply port, and the downstream side seal conveys toner in the rotational direction, using obliquely tilted capillary bundles to guide toner back to the supply port, preventing leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a felt member with non-unidirectional fibers is used in the side sealing member, then the structure is simple and easy to manufacture, but developer enters the felt member and is moved away from the supply port causing toner leakage

Engineering Contradiction:
Improveease of manufactureVSAvoidreliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The felt member is configured with unidirectional fibers arranged in a specific direction to create different functional zones. The fiber orientation is designed to allow developer entry from one side while preventing movement in unwanted directions, thus achieving both manufacturing simplicity and reliable sealing functionality

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention changes the fiber orientation parameter of the felt member from non-unidirectional to unidirectional. This parameter change fundamentally alters the developer flow characteristics, preventing toner leakage while maintaining the simple felt member structure that is easy to manufacture

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the side sealing member allows developer to enter freely, then the sealing structure is simple, but toner leakage occurs due to sliding contact moving developer away from the supply port

Engineering Contradiction:
Improvedevice complexityVSAvoidtoner leakage
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The felt member is configured with unidirectional fibers arranged in a specific direction to create different functional zones. The fiber orientation is designed to allow developer entry from one side while preventing movement in unwanted directions, thus achieving both manufacturing simplicity and reliable sealing functionality

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention converts the sliding contact between the felt member and developing roller, which initially causes harmful developer movement, into a beneficial mechanism. By orienting fibers unidirectionally, the sliding contact now serves to guide developer back toward the supply port, transforming the harmful effect into a useful developer return mechanism

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

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 effectively prevents toner leakage by ensuring toner is consistently returned to the supply port, maintaining image quality and preventing toner from escaping between the developing roller and the housing.

Implementation Method 1

sliding contact between the felt member and the developing roller

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

sliding contact between the felt member and the developing roller

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2113815B1Developing unit
Publication Date: 2015.08.05 BROTHER KOGYO KK
  • EP2113815B1 patent drawingFigure 1
  • EP2113815B1 patent drawingFigure 2
  • EP2113815B1 patent drawingFigure 3(a)~3(d)

AI summary

A developing unit is provided, which include: a developer carrier; a housing; and a side sealing member disposed between an end part of the developer carrier and a portion of the housing adjacent to a supply port. The side sealing member includes an upstream side seal and a downstream side seal. The upstream side seal is configured to convey a developer on the upstream side seal in an oblique direction toward the supply port and the downstream side. The downstream side seal is configured to convey a developer on the downstream side seal in a direction toward the downstream side.