Developing Device Communication Path Segmentation for Toner Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In separate-function type developing devices, developer with lowered toner density is communicated from the collection chamber to the supply chamber without agitation, leading to potential image defects due to non-uniform developer distribution and reduced toner density.
Innovation Solution
The developing device incorporates a configuration with a first and second communication portion in the partition wall, where the first communication portion defines a communication path from the collection chamber to the supply chamber, with specific areas and lengths to prevent unagitated developer transfer, ensuring adequate agitation and uniform distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a cutout portion is provided in the partition wall to permit developer communication from collection chamber to supply chamber, then device length is reduced, but developer with lowered toner density is communicated without agitation
Solution Approach 1:
The communication portion is divided into two distinct areas: a first area positioned within the developer coating area range and a second area positioned downstream of the developer coating area. This segmentation allows the upstream first area to enable communication while the downstream second area provides agitation space, preventing unagitated developer transfer while maintaining compact device length.
Solution Approach 2:
Different portions of the communication path are given different functions: the first area (upstream) facilitates developer communication from collection to supply chamber, while the second area (downstream) provides agitation space. This local differentiation ensures that developer is properly agitated before entering the supply chamber, maintaining toner density uniformity while keeping the device compact.
2Quantity of substance
If developer surface in collection chamber becomes high to reach cutout portion, then communication path is established, but developer whose toner density is lowered is communicated without being agitated
Solution Approach 1:
The communication portion is divided into a first area within the developer coating area range and a second area downstream of the developer coating area. This segmentation ensures that developer flows through both regions, allowing communication while ensuring agitation occurs in the second area before developer enters the supply chamber, maintaining toner density uniformity.
Solution Approach 2:
The communication path is designed to guide developer through the second area (downstream of coating area) before entering the supply chamber. This preliminary action ensures that developer is agitated in advance of entering the supply chamber, preventing unagitated developer transfer and maintaining toner density uniformity.
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 prevents the communication of low-toner-density developer from the collection chamber to the supply chamber without agitation, reducing image defects such as density irregularities and ensuring a consistent developer supply, thereby enhancing image quality.
Implementation Method 1
a first conveyance screw portion disposed in the first chamber and configured to convey the developer in the first chamber in a first conveyance direction, a second conveyance screw portion disposed in the second chamber, including a rotatable shaft portion, and configured to convey the developer in the second chamber in a second conveyance direction opposite to the first conveyance direction
Data Source
AI summary
A developing device includes a first communication portion defining a communication path through which developer in a second chamber is communicated to a first chamber. The communication path has a first area and a second area. The first area is positioned within a range corresponding to a developer coating area of a developer bearing member in a conveyance direction of developer in the collection chamber, while the second area is positioned downstream of the developer coating area in the conveyance direction. A first length of the first area is shorter than a second length of the second area. The first length is a maximum length from a bottom surface portion of the communication path to an upper portion of the first area, and the second length is a maximum length from the bottom surface portion of the communication path to an upper portion of the second area.