Dual-Seal Developing Device Toner Scattering Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing development devices face challenges in preventing toner scattering and accumulation, which can lead to image quality degradation and contamination within electrophotographic image forming apparatuses, despite the use of scattering prevention sheets and seal members, as these components can become electrically charged and adhere toner, causing issues with image formation.
Innovation Solution
The development device incorporates a dual-seal system with a first seal member fixed to the development casing and a second seal member that hangs under its own weight, along with an electroconductive member connected to the developer bearer, to prevent toner scattering and accumulation by minimizing electrical charge accumulation and reducing stress on the toner, while maintaining image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a scattering prevention sheet is provided to fill the clearance between the rim of the development casing and the latent image bearer, then developer scattering is prevented, but the sheet becomes charged and adheres toner particles causing accumulation
Solution Approach 1:
The patent introduces an electroconductive member as an intermediary component between the scattering prevention sheet and the toner particles. This electroconductive member is connected to the developer bearer and serves to neutralize electrical charges on the sheet, preventing toner adhesion while maintaining the sheet's function in preventing developer scattering.
Solution Approach 2:
The patent changes the electrical parameter (charge state) of the scattering prevention sheet by connecting it to the electroconductive member which is electrically linked to the developer bearer. This parameter change from charged to neutral/grounded state eliminates the harmful adhesion effect while preserving the mechanical function of the sheet.
2Object-affected harmful factors
If an insulative seal member is provided around the development roller, then toner scattering is prevented, but the seal member becomes charged and adheres toner particles
Solution Approach 1:
The patent employs a composite seal member structure combining insulative material (for sealing function) with electroconductive material (for charge dissipation). The electroconductive member is integrated with the insulative seal member, allowing the seal to prevent toner scattering while the conductive component neutralizes electrical charges to prevent toner adhesion.
Solution Approach 2:
The electroconductive member acts as an intermediary between the insulative seal member and the toner particles. It is connected to the developer bearer and serves to neutralize electrical charges on the seal member, preventing toner adhesion while maintaining the seal's function in preventing toner scattering.
3Object-affected harmful factors
If the seal member is fixed rigidly to prevent toner scattering, then scattering is prevented, but stress is applied to the toner causing image quality degradation
Solution Approach 1:
The patent transforms the rigid fixed seal member into a dynamic structure where the electroconductive member can move or flex relative to the seal member. This dynamic configuration allows the seal to adapt to toner flow and development roller movement, preventing toner scattering while minimizing stress application to the toner particles.
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 inhibits toner scattering and accumulation, reducing stress on the toner and preventing image degradation, thereby ensuring high-quality image formation and reducing maintenance needs.
Implementation Method 1
an electroconductive member connected to the developer bearer, to prevent toner scattering and accumulation by minimizing electrical charge accumulation
Implementation Method 2
a second seal member that hangs under its own weight
Data Source
AI summary
A development device includes a development casing, a developer bearer disposed facing a latent image bearer through an opening formed in the development casing, a magnetic field generator, a developer regulator disposed facing the developer bearer, a first seal member to cover a clearance between the latent image bearer and a rim of the development casing upstream from the opening, and a second seal member. The first seal member includes a first end portion fixed to the rim of the development casing and a second end portion in contact with the latent image bearer, and the second seal member includes a first end portion fixed to an inner face of the development casing farther from the latent image bearer than the first seal member, and a second end portion hanging to contact the developer carried on the developer bearer downstream from the developer regulator.