Developing Device Dispersing Structure for Uniform Image Density
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Solution Overview
Problem
Existing image forming apparatuses face challenges in achieving uniform developer dispersibility and image formation with even density due to inadequate developer stirring and conveyance mechanisms.
Innovation Solution
A developing device with a developer container, a conveying member, and a developer carrying member, featuring a helically formed conveying blade with a cut portion and a dispersing portion that extends radially, promoting developer dispersion and uniform image formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional conveying blade is used without cut portions or dispersing portions, then the structure is simple, but the developer dispersibility is poor and uneven density occurs
Solution Approach 1:
The conveying blade is divided into multiple functional regions: a continuous conveying portion for transporting developer, and a cut portion with dispersing surfaces for enhancing dispersion. This segmentation allows different sections to perform specialized functions, improving overall developer uniformity without excessive complexity
Solution Approach 2:
The dispersing surfaces are strategically positioned at specific locations where developer stagnation tends to occur. The cut portions create localized dispersing zones with radially extending surfaces that have areas larger than the conveying blade cross-section, providing enhanced dispersion exactly where needed rather than uniformly throughout the entire blade
2Manufacturing precision
If the conveying blade continuously stirs the developer, then the developer is well-mixed, but dead zones and stagnation areas are formed reducing dispersibility
Solution Approach 1:
Instead of using a continuous solid blade that creates rigid stirring patterns with dead zones, the invention introduces cut portions that create open spaces and radially extending dispersing surfaces. This inverted approach allows developer to flow through and around the dispersing surfaces from multiple directions, eliminating stagnation areas while maintaining effective mixing
3Manufacturing precision
If the dispersing surface area is small, then the conveying blade structure is simple, but the developer dispersibility remains insufficient
Solution Approach 1:
The dispersing surfaces extend in the radial direction from the rotation shaft, creating a three-dimensional dispersing structure rather than a simple two-dimensional surface. This radial extension increases the effective dispersing surface area and creates multiple interaction points with the developer, enhancing dispersion effectiveness without proportionally increasing structural complexity
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
Enhances developer dispersibility and uniformity, ensuring consistent image quality by stabilizing toner concentration and preventing stagnation, thereby improving image density uniformity.
Implementation Method 1
The conveying blade is helically formed on an outer circumferential part of the rotation shaft
Implementation Method 2
The dispersing surface has an area larger than the sectional area of the conveying blade
Data Source
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AI summary
A developing device (40) includes a developer container (50), a conveying member (42), and a developer carrying member (44). The conveying member (42) has a rotation shaft (42a), a conveying blade (42b), a cut portion (42c), and a dispersing portion (42e). In the cut portion (42c), the conveying blade (42b) is partly cut off along the longitudinal direction of the developer container (50). The dispersing portion (42e) is formed on an outer circumferential part of the rotation shaft (42a), so as to face the cut portion (42c), and extends along the radial direction of the rotation shaft (42a). The dispersing portion (42e) has a dispersing surface (42f) having an area larger than the sectional area of the conveying blade (42b).