Developing Device Magnetic Roller Separates Reverse Polarity Particles
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Solution Overview
Problem
The existing two-component developing systems for electrostatic latent images face issues with carrier deterioration and reduced service life due to contamination, leading to problems like fogging and toner scattering, especially when forming images with small image areas, and existing solutions either incur high costs or environmental concerns or fail to maintain initial properties effectively.
Innovation Solution
A developing device and method that incorporates a developer tank with toner, a carrier, and reverse polarity particles, utilizing a separating mechanism with a magnetic roller and sleeve roller to separate toner from the developer and return reverse polarity particles to the tank, preventing carrier deterioration and maintaining charge properties effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If reverse polarity particles are added to the developer, then carrier deterioration is prevented and service life is extended, but reverse polarity particles are consumed excessively when forming images with small image areas
Solution Approach 1:
The patent extracts reverse polarity particles from the developer after they have performed their function of preventing carrier deterioration. A separation mechanism removes these particles from the developer loop, preventing their consumption while maintaining their beneficial effects on carrier protection.
Solution Approach 2:
The patent implements a system to recover reverse polarity particles after use. The separation mechanism collects particles that have accumulated on the carrier surface and returns them to the developer tank, enabling reuse and preventing excessive consumption while maintaining carrier protection.
2Loss of substance
If a separating mechanism is introduced to recover reverse polarity particles, then particle consumption is reduced, but device complexity increases
Solution Approach 1:
The separating mechanism is designed to perform multiple functions: it separates reverse polarity particles from the developer, collects them for recovery, and returns them to the developer tank. This multi-functionality reduces the need for separate systems and minimizes overall device complexity.
Solution Approach 2:
The patent merges the separation, collection, and return functions into an integrated system within the developing device. The separating mechanism is combined with the existing developer circulation system, reducing the need for separate components and simplifying the overall structure.
3Reliability
If carrier is exchanged to prevent deterioration, then charge property is maintained, but costs increase and environmental preservation is compromised
Solution Approach 1:
The patent enables the carrier to self-renew by accumulating reverse polarity particles on its surface during operation. This natural accumulation process maintains charge property without requiring external intervention or carrier replacement, reducing costs and environmental impact.
Solution Approach 2:
The patent prepares reverse polarity particles in advance that can be accumulated on the carrier surface to prevent deterioration. These particles are pre-added to the developer and naturally accumulate on the carrier during normal operation, providing proactive protection before significant deterioration occurs.
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 effectively prevents carrier degradation and maintains the charge properties of toner for a long time, even with small image areas, while reducing the consumption of reverse polarity particles and ensuring a stable image-forming process with improved cleaning performance.
Implementation Method 1
a separating mechanism comprising a toner-supporting member which is installed between the developing area and the developer-supporting member and is configured to separate the toner from the developer supported on the developer-supporting member... configured to collect the developer from which toner has been separated in the developer tank by a repulsive magnetic field of the magnetic roller
Implementation Method 2
the two-component developing system, which charges the toner through a friction-charging process upon mixing with the carrier
Data Source
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AI summary
A developing device (2a), which is provided with: a developer tank (16) that houses a developer (24) containing a toner, a carrier for charging the toner and reverse polarity particles that are charged with a polarity reversed to the electrostatic charge polarity of the toner by the carrier; a developer-supporting member (11) that supports the developer supplied from the developer tank on the surface thereof, and transports the developer; and a separating mechanism (22) that separates the toner or the reverse polarity particles from the developer supported on the developer-supporting member, and the reverse polarity particles are collected into the developer tank, is provided, and an image-forming apparatus having such a developing device and an image-forming method applied thereto are also provided.