Dual Toner Collection Screw Feed for Leak-Safe Container Exchange

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Solution Overview

Problem

Existing image forming apparatuses face issues with high risk of leakage and scattering of collected developer during container exchange, leading to reduced productivity in high-volume printing operations, and require complex structural solutions to prevent such leakage.

Innovation Solution

The apparatus incorporates a feeding device with a helical screw conveyor that selectively directs collected developer into two developer collecting containers, reducing the risk of leakage and scattering by optimizing the conveyance path and using a single shutter mechanism to manage discharge openings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a single developer collecting container is used, then the structure is simple, but productivity decreases due to stopping operations during container exchange

Engineering Contradiction:
Improvecontinuous operation capabilityVSAvoidstructure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The single developer collecting container is divided into two separate containers (first and second collecting containers). This segmentation allows the system to switch between containers, enabling continuous operation when one container is being exchanged while the other is collecting developer, thus improving productivity without significantly increasing overall system complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The feeding device is designed with multi-functionality to feed collected developer to either the first or second collecting container based on operational needs. This universal feeding capability allows the system to maintain continuous operation while managing multiple containers, resolving the contradiction between productivity improvement and device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If multiple discharging openings are provided for selective discharge, then continuous operation is enabled, but the risk of toner leakage and scattering increases

Engineering Contradiction:
Improvecontinuous operation capabilityVSAvoidtoner leakage and scattering
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The harmful factor of toner leakage is extracted and isolated by providing a covering member that selectively covers the second discharging opening when the first collecting container is in use. This extraction approach allows the system to maintain multiple discharging openings for continuous operation while preventing toner leakage through the non-active opening

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A covering member is introduced as an intermediary element between the discharging openings and the external environment. This mediator selectively covers the inactive discharging opening, preventing toner leakage and scattering while allowing the system to benefit from having multiple discharging openings for continuous operation

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If shutter members are added to prevent toner leakage, then leakage risk decreases, but device complexity and size increase

Engineering Contradiction:
Improvetoner leakage preventionVSAvoidshutter member structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Instead of using complex shutter members that require precise mechanical control and add significant device complexity, the patent employs a simpler covering member that can be easily positioned to cover the inactive discharging opening. This simplified approach effectively prevents toner leakage without the complexity and size increase associated with traditional shutter mechanisms

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 minimizes the risk of developer leakage and scattering while allowing continuous operation during container exchange, maintaining productivity in high-volume printing without complicating the apparatus structure.

Implementation Method 1

a helical screw rotatable about a rotation axis along the lateral feeding passage; and a driving portion configured to rotationally drive the helical screw in a normal direction and a reverse direction

Methodology Applied
Scientific EffectHelical screw mechanism: Archimedes Screw

Data Source

PatentEP3896527B1Image forming apparatus
Publication Date: 2026.05.20 CANON KK
  • EP3896527B1 patent drawingFigure 1
  • EP3896527B1 patent drawingFigure 2
  • EP3896527B1 patent drawingFigure 3(a)~3(b)

AI summary

An image forming apparatus includes an image forming portion, a first collecting container, a second collecting container, and a feeding device. The feeding device includes a lateral feeding passage capable of feeding the toner, discharged from the image forming portion, in a direction crossing a vertical direction. The lateral feeding passage includes a first discharging opening, a second discharging opening, and a receiving opening provided between the first and second discharging openings, for receiving toner discharged from the image forming portion. The feeding device includes a helical feeding member rotatable about a rotation axis along the lateral feeding passage, and a driving portion for rotationally drive the helical feeding member in a normal direction and a reverse direction.