Developing Apparatus Screw Opening Geometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional developing apparatuses using multiple thread screw members for developer feeding experience circulation imbalances, leading to stagnation and overflow issues, and increased size requirements that are not space-efficient, especially when the partition wall extends long and the side walls are arcuately shaped.
Innovation Solution
A developing apparatus design featuring a first screw with a multiple thread screw portion and a second screw with a single thread screw portion, where the opening between the chambers extends from the downstream end of the multiple thread screw portion towards the upstream side by a length equal to or more than the product of the number of threads and thread pitch, ensuring balanced developer circulation and preventing stagnation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a multiple thread screw member is used to feed developer uniformly, then developer feeding uniformity is improved, but circulation imbalance and stagnation occur at the opening
Solution Approach 1:
The patent applies local quality by making the side walls arcuately shaped specifically at the opening region where developer circulation occurs, while other portions of the chamber maintain simple planar walls. This localized geometric modification creates favorable flow patterns that prevent stagnation and overflow at the opening while preserving the uniform feeding capability of the multiple thread screw member throughout the chamber.
2Reliability
If the partition wall extends long to separate chambers, then developer circulation control is improved, but device size increases
Solution Approach 1:
The patent employs curvature by shaping the side walls at the opening as arcs rather than using straight planar surfaces. This arcuate geometry allows the partition wall to be shorter while still effectively controlling developer circulation between chambers. The curved surfaces guide developer flow more efficiently, reducing the need for extended partition walls and thereby compacting the overall chamber volume.
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 prevents developer stagnation and overflow, maintaining image quality and density while optimizing space usage by ensuring smooth developer feeding and circulation, even at increased process speeds.
Implementation Method 1
at least one of the first screw and the second screw has a multiple thread screw portion having a number n of threads and a thread pitch P
Implementation Method 2
the opening is located downstream from the multiple thread screw portion in a developer feeding direction and extends from a downstream-side end of the multiple thread screw portion in the developer feeding direction toward an upstream side of the multiple thread screw portion in a length equal to or more than nP
Data Source
AI summary
A developing apparatus includes a developer container for containing a developer; a first screw, provided in a first screw, provided in a first chamber in the developer container, for feeding the developer; a second screw, provided in a second chamber in the developer container, for feeding the developer in a direction opposite from that of the first screw; an opening through which the developer is moved between the first chamber and the second chamber; and a developer carrying member, provided in the first chamber, for carrying the developer to effect development of an electrostatic image. At least one of said first screw and said second screw has a multiple thread screw portion having a number n of threads and a thread pitch P. The opening is located downstream from the multiple thread screw portion in a developer feeding direction and extends from a downstream-side end of the multiple thread screw portion in the developer feeding direction toward an upstream side of the multiple thread screw portion in a length equal to or more than nP.