Developer Holding Member With Random Surface Depressions
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Solution Overview
Problem
Existing developer holding members in image forming apparatuses face issues with toner adhesion to fine asperities, leading to decreased development performance and complex manufacturing processes, resulting in density unevenness and reduced image quality over time.
Innovation Solution
A developer holding member with a magnetic field generating device and a hollow body featuring randomly distributed depressions on its external surface, where the peak intensity of the spectrum within a specific wavelength range is controlled, and magnetic particles with a resin coating film are used to maintain consistent developer pick-up and prevent adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fine asperities are formed on the developing sleeve surface, then developer pick-up performance is improved, but toner adhesion to asperities occurs causing density unevenness and decreased development performance over time
Solution Approach 1:
The invention changes the surface morphology parameters from fine asperities to ridge-like protrusions with specific dimensional characteristics (width 0.01-0.1mm, height 0.01-0.05mm, spacing 0.05-0.5mm). This parameter modification maintains developer pick-up capability while preventing toner adhesion that causes density unevenness, thereby resolving the contradiction between productivity and reliability.
2Reliability
If ridge-like protrusions with fine asperities are formed on the developing sleeve, then development performance is improved, but manufacturing processing becomes complicated
Solution Approach 1:
The invention specifies precise dimensional parameters for the ridge-like protrusions (width 0.01-0.1mm, height 0.01-0.05mm, spacing 0.05-0.5mm) that can be achieved through standard machining processes. This parameter optimization simplifies manufacturing compared to forming fine asperities, while maintaining reliable development performance.
3Ease of manufacture
If the developing sleeve surface is made smooth, then manufacturing is simplified, but developer pick-up performance decreases
Solution Approach 1:
The invention applies local quality modification by creating ridge-like protrusions with specific dimensions (width 0.01-0.1mm, height 0.01-0.05mm) at strategic locations on the developing sleeve surface. These localized features enhance developer pick-up performance without requiring the entire surface to be complex, thus maintaining manufacturing simplicity while improving 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
The solution ensures stable and high-quality image formation over a long duration by reducing stress on the developer, preventing density unevenness, and simplifying the manufacturing process, while maintaining consistent pick-up performance.
Implementation Method 1
attracting a developer to an external surface thereof with magnetic force of the magnetic field generating device
Data Source
AI summary
A developer holding member includes a magnetic field generating device and a hollow body including the magnetic field generating device thereinside, and attracting a developer to an external surface thereof with magnetic force of the magnetic field generating device. The external surface of the hollow body is randomly provided with a large number of depressions, and a peak intensity of a spectrum within a range of wavelengths not more than 1 mm, which is figured out by performing a frequency analysis using a profile curve in a circumferential direction of the external surface, is not more than 12.