Two-Component Developer Magnetic Brush Gap Control
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Solution Overview
Problem
Image forming apparatuses experience rear end enhancement due to excessive toner development and sweeping by magnetic brushes, primarily caused by a high relative speed between the photoconductor drum and the developing roller, and a strong fringe electric field.
Innovation Solution
The developing device employs a two-component developer with a magnetic brush that maintains a specific distance (125-250 μm) and contact width (1.0-2.25 mm) with the photoconductor drum, and a developer density (0.75×10−6 to 1.50×10−6 g/m3) to mitigate toner sweeping and excessive development, thereby reducing rear end enhancement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the relative speed between the photoconductor drum and the developing roller is increased to improve processing speed, then productivity is improved, but rear end enhancement occurs due to excessive toner development and sweeping by magnetic brushes
Solution Approach 1:
The patent applies parameter changes by precisely controlling the gap between the developing roller and photoconductor drum (125-250 μm), the contact width (1.0-2.25 mm), and the developer density (0.75×10−6 to 1.50×10−6 g/m3). These parameter optimizations reduce toner sweeping and excessive development at high speeds while maintaining productivity
Solution Approach 2:
The patent applies local quality by creating a localized magnetic brush contact region with specific characteristics (125-250 μm gap, 1.0-2.25 mm contact width) rather than uniform contact across the entire surface. This localized approach reduces excessive toner development at the contact region while maintaining overall development effectiveness
2Manufacturing precision
If the magnetic brush contact width is increased to improve development coverage, then manufacturing precision is improved, but toner sweeping and excessive development increase causing rear end enhancement
Solution Approach 1:
The patent optimizes the contact width parameter to a specific range (1.0-2.25 mm) that provides sufficient development coverage while preventing excessive toner sweeping. This precise parameter control balances coverage and harmful effects
Solution Approach 2:
The patent applies partial action by limiting the magnetic brush contact to a specific region (1.0-2.25 mm width) rather than full-contact or excessive contact. This partial contact provides sufficient development while avoiding the harmful effects of excessive toner sweeping
3Manufacturing precision
If the developer density is increased to improve development effectiveness, then manufacturing precision is improved, but toner sweeping and rear end enhancement increase
Solution Approach 1:
The patent optimizes developer density to a specific range (0.75×10−6 to 1.50×10−6 g/m3) that ensures effective development while preventing excessive toner sweeping and rear end enhancement. This precise parameter optimization balances effectiveness and harmful effects
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 effectively suppresses rear end enhancement, maintaining image quality and prevent developer jamming, even at high processing speeds and varying surface energies, ensuring reliable and efficient image formation.
Implementation Method 1
The two-component developer is carried and transported by the developer transporting member of the developing device while a magnetic brush is formed
Data Source
AI summary
A two-component developer includes toner and a magnetic carrier. The two-component developer is used in a developing device including a circular cylindrical developer transporting member that is disposed so as to be separated by 125 μm to 250 μm from a latent image carrier that rotates. The two-component developer is used so as to satisfy a condition in which a width of a region where a magnetic brush contacts a surface of the latent image carrier is in a range of from 1.0 mm to 2.25 mm, and a condition in which a developer density of the region where the magnetic brush contacts the surface of the latent image carrier is in a range of from 0.75×10−6 to 1.50×10−6 g/m3.