Toner Regulating Blade Roughness for Ghost Prevention
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Solution Overview
Problem
Conventional image forming methods in electrophotography face challenges in achieving high-speed, long-term reliability with high-resolution and high-minuteness images, particularly with toners having high developing performance, due to issues like charge-up, uneven toner layer formation, and instability in environmental conditions.
Innovation Solution
The method involves a toner regulating blade with a specific surface roughness and area ratio, combined with toners containing a binder resin, magnetic material, and fine silica particles, to control toner layer thickness and charge uniformity, preventing sleeve negative ghosts and ensuring superior developing performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a toner with high developing performance (smaller particle diameter, sharper particle size distribution) is used, then image resolution and minuteness are improved, but charge-up occurs due to differences in chargeability and powder characteristics
Solution Approach 1:
The patent applies parameter changes by precisely controlling the surface roughness (Rz: 0.3-20μm) and contact area ratio (8/92 to 70/30) of the toner regulating blade, as well as optimizing toner properties (average particle diameter 3-400μm, circularity ≥0.930, aerated bulk density relationship). These parameter optimizations enable high-resolution imaging while maintaining charge stability through improved toner layer uniformity.
2Productivity
If a toner with high developing performance is used, then developing efficiency is improved, but the toner cannot be thin-layer coated uniformly on the toner bearing member
Solution Approach 1:
The patent optimizes the surface roughness parameter (Rz: 0.3-20μm) and contact area ratio (8/92 to 70/30) of the toner regulating blade to achieve uniform thin-layer coating. This enables high developing efficiency while maintaining consistent toner layer thickness across the bearing member surface.
Solution Approach 2:
The patent replaces conventional mechanical blade contact with a optimized friction-based toner regulation system. By controlling the surface characteristics and contact parameters of the toner regulating blade, the system achieves uniform toner distribution through friction and adhesion mechanisms rather than pure mechanical contact.
3Ease of manufacture
If conventional toner regulating blades are used, then manufacturing simplicity is maintained, but running stability is insufficient especially with one-component magnetic toners
Solution Approach 1:
The patent maintains manufacturing simplicity while improving running stability by optimizing specific parameters of the toner regulating blade: surface roughness (Rz: 0.3-20μm) and contact area ratio (8/92 to 70/30). These parameter changes enhance the blade's interaction with one-component magnetic toners, ensuring stable performance without complicating the manufacturing process.
4Manufacturing precision
If a toner regulating blade with high surface roughness is used, then toner layer thickness control is improved, but sleeve negative ghosts occur
Solution Approach 1:
The patent precisely optimizes the surface roughness parameter (Rz: 0.3-20μm) to achieve the right balance. This controlled roughness provides sufficient toner layer thickness control while preventing the excessive toner accumulation that causes sleeve negative ghosts, thereby eliminating this harmful effect.
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 approach enhances developing performance, maintains image density uniformity, and prevents toner adhesion issues, achieving stable and high-quality image formation across various environments.
Implementation Method 1
a toner regulating blade made of rubber or metal, serving as a toner layer thickness control member for controlling a toner coat level, is kept in contact with the surface of a developing sleeve
Implementation Method 2
through the toner bearing member, which has thinly been coated on its surface with the toner by the aid of the toner regulating blade, the toner is allowed to fly and adhere to the electrostatic latent image
Implementation Method 3
forming an electrostatic latent image on an electrostatic latent image bearing member by utilizing a photoconductive material
Implementation Method 4
the toner is allowed to fly and adhere to the electrostatic latent image formed on the surface of the electrostatic latent image bearing member, standing opposite to the toner bearing member, to perform development
Data Source
AI summary
An image forming method and related process cartridge, the method having the steps of controlling the layer thickness of a toner on a toner bearing member by means of a toner regulating blade, and developing with the toner an electrostatic latent image formed on an electrostatic latent image bearing member, the toner regulating blade has, at its part to be kept in touch with the toner bearing member, a specific ten-point average roughness Rz and a specific ratio (area of contact portion/area of non-contact portion) at a specific face pressure, and the toner has a specific average circularity and has a specific aerated bulk density. This image forming method and process cartridge promise superior developing performance in any environment, can keep sleeve negative ghost from occurring and can keep toner melt adhesion to toner regulating blade and toner melt adhesion to toner bearing member from occurring.