Development Sleeve Roughness for Developer Conveying
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Solution Overview
Problem
Conventional development devices face issues with developer deterioration, reduced developer conveying performance, and image quality degradation due to additive agent embedding, surface film wear, and uneven developer distribution, leading to irregularities in image formation.
Innovation Solution
A development device featuring a cylindrical magnetic field-generation member with a non-magnetic hollow member and a developer control system that includes a developer removing pole for separating thin toner developers and a pumping pole for controlled developer circulation, preventing excessive attraction and ensuring consistent developer supply to the image supporter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a roughened process (sandblast, grooved) is provided on the development sleeve surface to improve developer feeding, then developer conveying performance is improved, but the surface film of the carrier wears out faster and additive agents embed into the surface
Solution Approach 1:
The invention changes the surface parameters of the development sleeve by providing a roughened surface with specific characteristics (average roughness Ra of 0.3-2.0 μm, valley depth 1-5 μm). This controlled parameter change improves developer conveying while minimizing carrier wear and additive embedding, resolving the contradiction between productivity and reliability.
2Productivity
If the development sleeve rotates at high speed to improve image formation efficiency, then productivity is improved, but developer feeding becomes insufficient due to slipping on the smooth surface
Solution Approach 1:
The invention modifies the surface parameters of the development sleeve by creating a roughened surface with controlled roughness (Ra 0.3-2.0 μm) and valley depth (1-5 μm). This parameter change increases friction between the developer and sleeve surface, preventing slipping at high rotation speeds and ensuring stable developer feeding while maintaining high productivity.
3Manufacturing precision
If a magnet roller with multiple magnetic poles is used to form raised portions of developer, then developer distribution is improved, but the structure becomes more complex and costly
Solution Approach 1:
The invention applies local quality by providing a roughened surface only on the development sleeve where developer contact occurs, rather than complexing the entire magnet roller structure. The roughened surface locally improves developer adhesion and distribution without requiring additional magnetic poles or complex mechanisms, reducing device complexity while maintaining manufacturing precision.
4Reliability
If the development sleeve surface is made smooth to reduce carrier wear, then reliability is improved, but developer feeding becomes insufficient at high rotation speeds
Solution Approach 1:
The invention optimizes the surface parameters of the development sleeve by creating a controlled roughness (Ra 0.3-2.0 μm) that is sufficient to improve developer conveying at high speeds but not so rough as to cause excessive carrier wear or additive embedding. This balanced parameter change resolves the contradiction between reliability and 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
This configuration prevents developer deterioration, maintains high image quality, and ensures consistent developer distribution, reducing irregularities and maintaining image quality over time without the need for complex working processes.
Implementation Method 1
a magnetic field-generation member having a surface portion provided with a plurality of magnetic poles... configured to form a magnetic field for generating ears or raised portions of the developer on a surface of the development sleeve
Implementation Method 2
a developer removing pole provided on the surface portion of the magnetic field-generation member to form a developer separation area for separating the developed developer which has a thin toner condense from the hollow member into the developer-containing tank
Data Source
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AI summary
A development device including a developer carrier including a cylindrical magnetic field-generation member having a surface portion provided with a plurality of magnetic poles and a rotatable hollow member which is disposed inside the magnetic field-generation member and formed of a non-magnetic material, a developer control member configured to control an amount of a developer which is carried on the developer carrier and fed to an image supporter disposed to face the developer carrier, and an agitator provided upstream the developer control member in a rotating direction of the developer carrier and configured to feed the developer contained in a developer-containing tank in an axial direction of the hollow member, a developer conveying pole being provided on the surface portion of the magnetic field-generation member to form a developer separation area for separating the developed developer which has thin toner density from the hollow member into the developer-containing tank on the surface portion of the hollow member, and only a developer pumping pole being provided downstream the developer conveying pole and between the developer control member and the agitator to pump the developer from the developer-containing tank.