Developing Device Side Seal Toner Leakage Control
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Solution Overview
Problem
Conventional developing cartridges fail to sufficiently restrict toner leakage from the outer case, especially at higher rotational speeds and with reduced toner particle sizes, which can lead to image quality issues and reduced service life.
Innovation Solution
A developing device with a side seal configuration that includes a first seal member made of flocked fabric and a second seal member, both of which are designed to work in conjunction with a film member and a thickness-regulating blade to prevent toner leakage by exerting forces and using materials with varying flexibility to manage toner movement effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the rotational speed of the developing roller is increased to improve image formation speeds, then productivity is improved, but toner leakage from the outer case increases
Solution Approach 1:
The side seal member is divided into multiple functional segments: an upstream-side seal with an elastic base material and surface member, and a downstream-side seal with an elastic base member and surface member. This segmentation allows each segment to perform specific functions - the upstream seal prevents toner from entering the side seal member while the downstream seal prevents toner from leaking outward, effectively controlling toner movement at different locations along the rotational path.
Solution Approach 2:
The patent changes the material parameters of the seal members by using elastic base materials with specific properties that can withstand high rotational speeds. The surface members are designed with appropriate friction characteristics to control toner movement. These parameter changes enable the seal system to maintain effectiveness even when the developing roller rotates at higher speeds for improved productivity.
2Temperature
If toner particle sizes are reduced for low-temperature fixing, then energy use is reduced, but toner leakage control becomes more difficult
Solution Approach 1:
The patent applies local quality by designing different seal structures for different locations. The upstream-side seal uses an elastic base material with a surface member configured to prevent small toner particles from penetrating inward, while the downstream-side seal uses a different elastic base member configuration to prevent particles from escaping outward. This localized differentiation allows effective control of fine toner particles at each critical location.
3Device complexity
If conventional seal members are used, then device complexity is low, but toner leakage restriction is insufficient
Solution Approach 1:
The side seal member employs composite materials by combining elastic base materials with surface members. The elastic base material provides flexibility and conformability to the developing roller surface, while the surface members provide specific friction and sealing properties. This composite structure achieves superior toner leakage prevention compared to conventional single-material seals, while maintaining reasonable device complexity through integrated design.
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
The solution effectively suppresses toner leakage, even at high rotational speeds and with smaller toner particles, thereby enhancing image formation quality and extending the service life of the developing cartridge.
Implementation Method 1
The contact member includes a first seal member and a second seal member... The second seal member is made of a material that restricts movement of the developer entering therein by the rotation of the developing roller
Data Source
Figure 1
Figure 2
Figure 3A~3C
AI summary
A developing device includes: a frame having an opening; a developer carrying member rotatably supported to the frame; and a side seal. The developer carrying member is rotatable about its axis in a rotating direction and has an axial end portion in an axial direction. The side seal is disposed between the frame and a peripheral surface of the axial end portion, and has a contact member contacting the peripheral surface. The contact member includes: a first seal member disposed adjacent to an edge of the opening in the axial direction; and a second seal member disposed adjacent to and upstream of the first seal member in the rotating direction. The first seal member permits developer to move inward in the axial direction and provides a mobility of developer therein higher than that of the second seal member that is made of a material that restricts movement of developer.