Developer Circulation Stabilization via Communication Port Design

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional developing apparatuses experience image unevenness and fluctuating torque loads due to unstable developer circulation and liquid surface fluctuations, which affect the flow of developer between accommodating chambers.

Innovation Solution

The developing apparatus ensures the developer is always positioned above the communication portion opening, with the opening upper end positioned below the liquid surface, and the communication portion is designed to maintain a stable flow by using spiral blades on the screws and setting the angle between screw rotations to 30 degrees or less, preventing uneven developer distribution and torque fluctuations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the communication portion is positioned in the center of the accommodating chamber, then the developer can flow between chambers, but the liquid surface fluctuation causes unstable flow amount and image unevenness

Engineering Contradiction:
Improvedeveloper flow amountVSAvoidflow stability
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The partition wall is designed with a specific local structure: the communication portion opening upper end is positioned at a height lower than the lowest liquid surface position. This localized structural feature ensures that the opening remains submerged below the liquid surface, creating a stable flow condition that is not affected by liquid surface fluctuations, thus resolving the contradiction between flow quantity and flow stability.

Inventive Principle:
Principle #3Local quality

2Productivity

If the communication portion is fully open without partition wall, then developer can flow freely, but the amount of flowing developer cannot be limited causing dispersion and image unevenness

Engineering Contradiction:
Improvedeveloper circulationVSAvoidflow amount control
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The partition wall is segmented with a specifically designed communication portion that has controlled openings. Instead of a fully open structure, the partition wall is divided into sections with precise opening positions and sizes, allowing developer circulation while controlling the flow amount to prevent dispersion and image unevenness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The opening position parameter of the communication portion is specifically set so that the opening upper end is lower than the lowest liquid surface position. This parameter change ensures that the effective opening area remains constant despite liquid surface fluctuations, providing precise flow amount control while maintaining circulation productivity.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the liquid surface position drops below the communication portion opening, then developer cannot flow between chambers, but this causes interruption in circulation and torque load fluctuation

Engineering Contradiction:
Improvecirculation continuityVSAvoidtorque load
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The communication portion opening is pre-positioned at a height lower than the lowest expected liquid surface position. This preliminary design ensures that even when the liquid surface drops to its lowest point, the opening remains submerged and developer flow is maintained, preventing circulation interruption and torque load fluctuation.

Inventive Principle:
Principle #10Preliminary action

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 stabilizes the developer circulation, prevents image unevenness, and maintains a consistent torque load on the screw, ensuring smooth developer flow and reduced fluctuations.

Implementation Method 1

arranging a screw in each of the formed accommodating chambers

Methodology Applied
Scientific EffectScrew mechanism: Screw

Implementation Method 2

move in a circulating manner a developer accommodated in a developer accommodating chamber while agitating

Methodology Applied
Scientific EffectMechanical force: Mechanical Force

Implementation Method 3

in the case that the liquid surface position of the developer becomes lower than a lower end of an opening of the communication portion, it is impossible to make the developer flow

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2259152B1Developing apparatus and image forming apparatus
Publication Date: 2019.09.04 KONICA MINOLTA BUSINESS TECH INC
  • EP2259152B1 patent drawingFigure 1
  • EP2259152B1 patent drawingFigure 2~3
  • EP2259152B1 patent drawingFigure 4~5

AI summary

A developing apparatus is provided with a developer accommodating container having a replenishing portion in which a developer including a toner and a carrier is accommodated, and provided for replenishing the developer, and a discharging portion for discharging the accommodated developer. The developer accommodating container is separated into a first accommodating portion and a second accommodating portion by a partition wall, and the first accommodating portion and the second accommodating portion are communicated with each other by communication portions in both end sides. The developing apparatus moves in a circulating manner the accommodated developer while agitating, by means of a first feeding member arranged in the first accommodating portion and a second feeding member arranged in the second accommodating portion. The communication portions are communicated below a supposed lowest height of a liquid surface of the developer.