Developer Chamber Layout to Prevent Backflow in Image Forming

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing developing devices face issues with developer uneven deterioration and image quality degradation due to shortcuts and backflows, leading to inefficient developer circulation and charging, which can result in developing failures.

Innovation Solution

The developing device incorporates a structure with separate return and agitation chambers, positioned to minimize developer shortcuts and backflows, and utilizes a charging film to electrostatically attract released developer, reducing the need for additional components and space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single chamber is used for both return and agitation of developer, then device complexity is reduced, but developer shortcuts and backflows increase causing uneven deterioration

Engineering Contradiction:
Improvechamber structureVSAvoiddeveloper circulation uniformity
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The developing device is divided into separate return chamber and agitation chamber. The return chamber receives developer from the developing roller and the agitation chamber agitates and supplies developer back to the developing roller. This segmentation prevents shortcuts and backflows, ensuring uniform developer circulation and preventing uneven deterioration.

Inventive Principle:
Principle #1Segmentation

2Reliability

If shielding plates with voltage application are used to return released developer, then developer control is improved, but device complexity and component count increase

Engineering Contradiction:
Improvedeveloper return controlVSAvoidshielding plate structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the electrical field-based developer return mechanism (shielding plates with voltage application) with a mechanical circulation system using separate return and agitation chambers. The magnetic brush and chamber structure mechanically guide and return released developer, eliminating the need for complex voltage application systems while achieving the same developer control function.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If developer container of third transporter and second transporter are not separated, then device complexity is reduced, but developer shortcuts occur causing uneven deterioration

Engineering Contradiction:
Improvetransporter container structureVSAvoiddeveloper circulation path control
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent separates the developer container into distinct return chamber and agitation chamber portions for the third transporter and second transporter respectively. This segmentation ensures that developer flows through the intended path without shortcuts, maintaining circulation precision and preventing uneven deterioration while the integrated chamber structure keeps overall device complexity low.

Inventive Principle:
Principle #1Segmentation

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 design suppresses developer uneven deterioration, reduces image quality issues, and minimizes component count and device size while ensuring effective developer circulation and charging.

Implementation Method 1

a charging film to electrostatically attract released developer

Methodology Applied
Scientific EffectElectrostatic attraction: Electrostatics

Data Source

PatentEP4530740B1Developing device and image forming apparatus
Publication Date: 2025.11.12 FUJIFILM BUSINESS INNOVATION CORP
  • EP4530740B1 patent drawingFigure 1
  • EP4530740B1 patent drawingFigure 2
  • EP4530740B1 patent drawingFigure 3

AI summary

A developing device includes a developer container that contains a developer, a developer carrier supported by the developer container and configured to carry the developer on a surface of the developer carrier, a first transporter configured to transport the developer in the developer container, disposed parallel to the developer carrier, and configured to supply the developer to the developer carrier, a second transporter configured to transport the developer in the developer container, disposed parallel to the first transporter, and configured to transport the developer in a direction opposite to a direction of the first transporter, a third transporter configured to transport the developer in the developer container, disposed parallel to the second transporter, and configured to transport the developer released from the developer carrier, a first container that contains the developer to be transported by the first transporter, a second container that contains the developer to be transported by the second transporter, a third container that contains the developer to be transported by the third transporter, a first partition that is disposed between the first container and the second container and separates the first container and the second container, a second partition that is disposed between the second container and the third container and separates the second container and the third container, a first inlet portion disposed on an upstream side of the first partition in a transport direction of the first transporter and configured to cause the developer to flow into the first container from the second container, a second inlet portion disposed on an upstream side of the first partition in a transport direction of the second transporter and configured to cause the developer to flow into the second container from the first container, and a third inlet portion disposed on an upstream side of the second partition in the transport direction of the second transporter and configured to cause the developer to flow into the second container from the third container.