Developing Device Removable Seals Prevent Developer Discharge

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Solution Overview

Problem

Existing image forming apparatuses face issues with unintended discharge of newly added developer, particularly due to uneven distribution at startup, leading to potential loss of new carrier and developer inefficiency.

Innovation Solution

A developing device with first and second chambers, a developing roller, and removable seals that initially block communication ports to prevent unintended discharge, ensuring the developer is contained in one chamber and discharged from the other, thereby maintaining even distribution and preventing premature discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the discharge unit is provided to discharge surplus carrier, then the carrier can be discharged when new carrier is added, but the newly added developer may be unintentionally discharged at startup due to uneven distribution

Engineering Contradiction:
Improvecarrier discharge efficiencyVSAvoiddeveloper discharge control
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The developing unit is divided into a first chamber and a second chamber separated by a partition wall. The first chamber contains the developing roller and receives newly added developer, while the second chamber contains the discharge unit. This segmentation prevents the newly added developer in the first chamber from being discharged through the discharge unit in the second chamber, solving the problem of unintended discharge at startup.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A partition wall acts as an intermediary barrier between the first chamber and the second chamber. The partition wall includes communication ports that can be opened or closed to control developer flow between chambers. This intermediary structure allows controlled interaction between chambers while preventing unwanted discharge of newly added developer.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the communication ports are opened to allow developer circulation, then the developer can flow between chambers, but the newly added developer may be discharged unintentionally

Engineering Contradiction:
Improvedeveloper circulationVSAvoidnew carrier loss
Core Design Contradiction:
Ease of operationVSLoss of substance

Solution Approach 1:

The partition wall is initially configured with closed communication ports before developer replenishment. After new developer is added to the first chamber, the communication ports can be opened to allow circulation. This preliminary closing action prevents new carrier loss during the replenishment process while still allowing circulation when needed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The communication ports in the partition wall are designed to be dynamically openable and closable. This dynamic configuration allows the system to adapt to different operational states: closed during developer replenishment to prevent loss, and open during normal operation to allow circulation and carrier discharge.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3709091B1Developing device, image forming unit, and image forming apparatus
Publication Date: 2023.06.07 TOSHIBA TEC KK
  • EP3709091B1 patent drawingFigure 1
  • EP3709091B1 patent drawingFigure 2
  • EP3709091B1 patent drawingFigure 3

AI summary

A developing device includes first and second chambers, a developing roller, first and second mixers, and one or more removable seals. The developing roller is in the first chamber. The first mixer is in the first chamber and configured convey developer in a first direction along a rotational axis of the developing roller. The second chamber is connected to the first chamber via a first port and a second port that are spaced apart from each other in in the first direction. The second mixer is in the second chamber and configured to perform convey developer in a second direction opposite to the first direction. The one or more removable seals cover the first and second ports . A developer is contained in one of the first or second chambers . A developer discharge port is provided on the other one of the first or second chambers.