Developer Suction Duct Structure to Prevent Filter Clogging

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Solution Overview

Problem

The increased speed of image forming apparatuses leads to clogging of filters and flow paths due to the accumulation of recovered developer, which is not effectively managed by existing recovery systems.

Innovation Solution

A developing apparatus with a suction duct featuring a developer separation structure that includes hanging and standing walls to change airflow direction, a developer receiver, and a transport mechanism to separate and recover developer efficiently.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the speed of the image forming apparatus is increased, then the productivity is improved, but the amount of recovered developer increases causing filter clogging

Engineering Contradiction:
Improvespeed of image forming apparatusVSAvoidfilter clogging
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The suction duct is segmented into multiple sections with hanging walls and standing walls arranged along the suction direction. These walls create multiple separation zones that progressively divide and separate developer particles from the airflow, preventing clogging while maintaining high-speed operation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Hanging walls and standing walls are introduced as intermediary structures within the suction duct. These walls act as mediators that change airflow direction and create separation zones, allowing developer particles to be separated from the airflow before reaching the filter, thus preventing clogging without reducing productivity

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the amount of recovered developer is increased, then the developer recovery efficiency is improved, but the deposition of developer on the flow path increases

Engineering Contradiction:
Improvedeveloper recovery efficiencyVSAvoiddeveloper deposition on flow path
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The hanging walls and standing walls are positioned to create separation zones before the developer reaches the filter. This preliminary separation action occurs within the suction duct itself, allowing developer particles to be removed from the airflow early in the process, preventing deposition on downstream components while maintaining recovery efficiency

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The separation structure utilizes three-dimensional space within the suction duct by arranging hanging walls (extending downward) and standing walls (extending upward) along the suction direction. This creates multiple separation planes and zones that maximize developer capture without increasing the cross-sectional area of the flow path, thus preventing deposition while maintaining recovery efficiency

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 suppresses filter clogging, enhances developer recovery, and reduces maintenance frequency by separating developer from airflow early and depositing it in a receiver for efficient discharge.

Implementation Method 1

separates the developer from an airflow by changing a direction of the airflow in the suction duct

Methodology Applied
Scientific EffectAirflow direction change:

Implementation Method 2

sucks the developer from an image holder side via the suction port

Methodology Applied
Scientific EffectSuction: Suction

Data Source

PatentEP4700491A1Developing apparatus and image forming apparatus
Publication Date: 2026.02.25 FUJIFILM BUSINESS INNOVATION CORP
  • EP4700491A1 patent drawingFigure 1
  • EP4700491A1 patent drawingFigure 2
  • EP4700491A1 patent drawingFigure 3

AI summary

A developing apparatus includes a developing roll that holds developer and is rotated; an image holder that is disposed to face the developing roll and is rotated; and a suction duct that is provided with a suction port formed to correspond to at least both end portions of the developing roll, sucks the developer from an image holder side via the suction port, and has a developer separation structure that is disposed adjacent to the suction port and separates the developer from an airflow by changing a direction of the airflow in the suction duct.