Developing Device Toner Mixing Agitation Control
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Solution Overview
Problem
Conventional developing devices face issues with maintaining a constant toner-to-carrier mixing ratio and toner charge in electrophotographic image forming apparatuses, leading to problems like toner flying and scumming, especially during high-speed operations, due to inefficient agitation and varying environmental conditions.
Innovation Solution
A developing device with a developing unit, a developer agitating unit, a developer conveying unit, and a toner supplementing unit that directly supplements toner to the developer before it reaches the agitating unit, ensuring efficient toner mixing and charge optimization through sensors and controlled agitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If toner is resupplied to a developer agitating unit to be mixed with developer with decreased toner density, then the toner density can be restored, but the low specific gravity of toner causes it to fly in the air or remain unmixed, requiring long agitation time
Solution Approach 1:
The patent applies preliminary action by performing toner agitation and charging in advance within the developer container before the developer is supplied to the developing device. This ensures that toner is properly mixed and charged before use, preventing flying and scumming without requiring extended agitation time during the development process.
Solution Approach 2:
The patent introduces an intermediary charging mechanism within the developer container that charges toner particles during the agitation process. This intermediary charging step facilitates better mixing by reducing electrostatic repulsion between toner particles and developer components, thereby reducing the overall agitation time required.
2Reliability
If the capacity of the developer is increased to sufficiently charge the resupplied toner, then charging is improved, but the size of the developing device is increased
Solution Approach 1:
The patent performs toner charging in advance within the developer container before the developer is supplied to the developing device. This preliminary charging action ensures sufficient toner charge without requiring a large developer capacity or increased device size, as the charging process is completed during the agitation phase within the compact container.
Solution Approach 2:
The patent merges the agitation and charging functions into a single integrated process within the developer container. By combining these functions, the system achieves sufficient toner charging without requiring separate large-capacity charging mechanisms, thereby maintaining a compact device size.
3Reliability
If two agitating portions are provided to agitate toner before supply, then toner charging is improved, but the apparatus size is increased
Solution Approach 1:
The patent merges the agitation and charging functions into a single integrated process within the developer container. This multi-functional design achieves effective toner charging and mixing without requiring separate agitating portions, thereby preventing an increase in apparatus size.
Solution Approach 2:
The developer container is designed to perform multiple functions: storing developer, agitating toner and developer, and charging toner particles. This multi-functionality eliminates the need for separate dedicated agitating portions, maintaining a compact apparatus size while ensuring reliable toner charging.
4Productivity
If high-speed machine operation is performed, then productivity is improved, but the circulation speed of developer is fast, preventing sufficient toner charging time
Solution Approach 1:
The patent performs toner charging in advance within the developer container before the developer is supplied to the developing device. This preliminary action ensures that toner is fully charged during the agitation phase, so that even at high circulation speeds during operation, sufficient charging time has already been provided, maintaining image quality at high productivity.
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 configuration reduces agitation time, prevents toner flying, and maintains consistent toner density and charge, enhancing image quality and reducing stress on the developer components.
Implementation Method 1
a transporting unit that transports the developer from the developer container to the developing unit via the developer supply member
Implementation Method 2
the toner and carrier are triboelectrically charged to cause an electric charge at the developer, thereby charging the toner
Data Source
AI summary
A developing device includes a developing unit, a developer agitating unit, a developer conveying unit, and a toner supplementing unit. The developing unit develops an electrostatic latent image on an image carrier with a developer containing toner and carrier. The developer agitating unit agitates the developer. The developer conveying unit connects the developing unit and the developer agitating unit, and conveys the developer from the developing unit to the developer agitating unit. The toner supplementing unit is connected to the developer conveying unit, and supplements toner to the developer conveyed from the developing unit to the developer agitating unit.