Developing Sleeve Control Member for Uniform Developer Layer
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Solution Overview
Problem
Existing developing devices face challenges in reducing stress on developers, leading to potential clogging and increased production costs due to complex arrangements and alignment requirements, which can result in deteriorated image quality and reduced productivity.
Innovation Solution
A developing device with a rotatable developing sleeve and a magnet roller having multiple magnetic poles, combined with a non-magnetic control member that is ferromagnetic and magnetic-field oriented, allows for uniform developer supply and stress reduction without increasing production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thickness control plate made of magnetic member and non-magnetic member is used to reduce stress on developer, then developer stress is reduced and image quality is stabilized, but alignment accuracy between members and assembly complexity increase production cost
Solution Approach 1:
The invention extracts the magnetic member from the thickness control plate and relocates it to the developing roller, separating the stress-reduction function from the thickness control function. This eliminates the alignment complexity between magnetic and non-magnetic members while maintaining developer stress reduction and image quality stability.
Solution Approach 2:
The invention merges the magnetic member with the developing roller structure, combining the thickness control and developer stress reduction functions into a single integrated component system. This simplifies assembly by eliminating the need for precise alignment between separate magnetic and non-magnetic members.
2Productivity
If small diameter carrier (30-50 μm) and small diameter toner (5-7 μm) are used to improve image quality and energy saving, then image quality and energy efficiency are improved, but developer is likely to congregate due to heat or stress
Solution Approach 1:
The invention applies a magnetic field as a counteracting force to oppose the harmful effects of heat and stress on the developer. The magnetic field generated by the magnetic member in the developing roller prevents developer conglomeration, allowing the use of fine-particle carrier and toner without compromising developer stability.
Solution Approach 2:
The invention changes the physical state and distribution parameters of the developer by introducing a magnetic field. This magnetic field modifies the behavior of fine-particle carrier and toner, preventing aggregation while maintaining the benefits of small particle sizes for improved image quality and energy efficiency.
3Manufacturing precision
If magnetic member and non-magnetic member are integrally formed by laser welding to ensure alignment accuracy, then alignment precision is improved, but manufacturing complexity and production cost increase
Solution Approach 1:
The invention segments the developing roller into distinct functional parts: a magnetic member portion for stress reduction and a non-magnetic member portion for thickness control. This segmentation eliminates the need for laser welding while maintaining functional independence and simplifying manufacturing processes.
Solution Approach 2:
The invention replaces the complex, expensive laser welding process with simpler assembly methods. The magnetic and non-magnetic members can be manufactured separately using conventional techniques and assembled without requiring precision welding, reducing manufacturing complexity and cost.
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 arrangement effectively reduces stress on developers, prevents clogging, and ensures stable image quality by maintaining developer uniformity and fluidity, thereby enhancing productivity and long-term image quality.
Implementation Method 1
capturing, on a surface of the developing sleeve, by magnetic force of the magnet roller, the developer contained in the developing tank
Implementation Method 2
the non-magnetic member being such that a nearest part of the non-magnetic member from the developing roller (i) has been caused to be ferromagnetic
Implementation Method 3
has been magnetic-field oriented
Data Source
AI summary
A developing device 2 includes a control member 116 for controlling an amount of a developer supplied to an image bearing member 3 by causing a developer captured on a surface of a developing sleeve 119 to be uniform in layer thickness. The control member 116 is arranged to face, via the developing sleeve 119, one (120b) of a plurality of magnetic poles provided inside the developing sleeve 119. Further, the control member 116 is arranged to be in parallel with a developing roller 114 in an axial direction of a magnet fixing shaft 126. The control member 116 is such a non-magnetic member that the nearest part of the non-magnetic member from the developing roller 114 has been caused to be ferromagnetic and has been magnetic-field oriented.