Developing Device Toner Mixing Arcuate Wall
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Solution Overview
Problem
Conventional developing devices with large volume developing chambers take a long time to mix new toner with degraded toner, leading to immediate image degradation after new toner supply due to polarity mismatch or aggregation.
Innovation Solution
A developing device with a developing unit and toner cartridge design featuring an arcuate bottom wall and protruding wall for efficient toner circulation, where the agitator's flexible sheet member ensures effective mixing and circulation between the toner cartridge and developing chamber, reducing the volume of degraded toner and promoting rapid toner exchange.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the developing chamber volume is increased to hold more toner, then the toner storage capacity is improved, but the mixing time between new and degraded toner increases
Solution Approach 1:
The developing chamber is segmented into an upper chamber and a lower chamber by a partition wall. The lower chamber contains a toner supply roller that actively feeds toner to the upper chamber, creating distinct functional zones that facilitate controlled toner flow and mixing while maintaining adequate storage capacity.
Solution Approach 2:
A flexible sheet member is introduced as a dynamic mixing element that moves with the toner flow. This flexible component actively agitates and mixes the toner between new and degraded portions without requiring a large chamber volume, thereby reducing mixing time while maintaining storage capacity.
2Loss of time
If the developing chamber volume is reduced to minimize degraded toner, then the mixing time is improved, but the toner storage capacity decreases
Solution Approach 1:
The partition wall extends vertically to divide the chamber into upper and lower sections. This vertical segmentation allows the system to maintain adequate toner storage capacity in the lower chamber while enabling rapid mixing and exchange in the upper chamber where the photosensitive drum operates, effectively separating storage function from mixing function.
Solution Approach 2:
The toner supply roller in the lower chamber preliminarily prepares and feeds fresh toner to the upper chamber before it reaches the mixing zone. This preliminary action ensures that new toner is continuously introduced and mixed with degraded toner in a controlled manner, reducing overall mixing time while maintaining storage capacity.
3Loss of time
If the agitator mixing action is intensified to reduce mixing time, then the image quality degradation is reduced, but the device complexity increases
Solution Approach 1:
The flexible sheet member utilizes the natural motion and flow of toner itself to achieve mixing. As toner moves through the chamber and contacts the flexible sheet, the sheet's natural flexibility and movement create effective agitation and mixing without requiring complex mechanical agitator structures, thereby reducing device complexity while maintaining efficient mixing.
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 reduces the time required for mixing new and degraded toner, minimizing image degradation immediately after new toner supply by efficiently circulating and mixing toner, while maintaining a compact device structure.
Implementation Method 1
a flexible sheet member (123) in sliding contact with the bottom wall (111) to agitate the developing agent
Data Source
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AI summary
A developing device (7) includes a developing unit (200) having a developing frame defining therein a developing chamber (70) and a developing roller (71) rotatably disposed in the developing chamber, and a developing agent unit including a developing agent container (110) that accommodates therein a developing agent, and an agitator (122) disposed in the developing agent container and rotatable about a rotation axis in a rotational direction to agitate the developing agent. The developing agent container includes an arcuate bottom wall (111) whose center of radius of a curvature is coincident with the rotation axis (C1), and an arcuate protruding wall (112) protruding from the bottom wall toward the developing chamber and positioned downstream of the bottom wall in the rotational direction. The protruding wall is formed with an opening (130) providing a fluid communication between an interior of the developing agent container and the developing chamber. The opening has a downstream end in the rotational direction in an operational state. The bottom wall and the protruding wall have inner surfaces extending diagonally upward from a lowermost point of the bottom wall to the downstream end in the operational state.