Magnet Roller Pole Length Variation for Toner Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional developing devices using magnetic sealing members fail to achieve stable sealing over time due to magnetic toner escaping from the development area, as the magnetic force is concentrated within the sealing member, leading to incomplete confinement of toner.
Innovation Solution
A developing device with a fixed magnet roller having multiple magnetic poles that create a magnetic force acting from the outer side to the inner side of the development sleeve, combined with a magnetic sealing member, effectively guiding toner back into the development area and maintaining stable sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If only a magnetic sealing member is provided, then the construction is simple, but sufficient sealing capability is not achieved and magnetic toner leaks outside the development area
Solution Approach 1:
The invention merges the sealing function with the magnetic field generation function by integrating a magnetic pole (either a fixed magnet or electromagnet) into the magnetic sealing member structure. This combination allows the sealing member to both confine toner through magnetic field and provide the necessary sealing force, achieving reliable sealing without adding separate complex components
Solution Approach 2:
The invention introduces a magnetic pole as an intermediary element that generates a magnetic field to act on the magnetic toner. This magnetic field serves as the mediating force that enables the magnetic sealing member to effectively confine and control the magnetic toner, preventing leakage while maintaining construction simplicity
2Reliability
If the magnetic force is concentrated within the magnetic sealing member, then the sealing structure is compact, but the magnetic toner is pushed outside the development area and sealing becomes unstable over time
Solution Approach 1:
The invention applies local quality by positioning the magnetic pole such that the magnetic field is concentrated at the critical sealing location where the magnetic sealing member contacts or approaches the development sleeve. This localized magnetic field application ensures effective toner confinement at the sealing point without requiring uniform magnetic force distribution throughout the entire structure, maintaining compactness while achieving stable sealing
Solution Approach 2:
The magnetic pole is positioned and configured in advance to create a preliminary magnetic field that proactively prevents toner from escaping toward the magnetic sealing member. This preliminary magnetic action keeps the toner layer thickness controlled and prevents the buildup that would otherwise push toner outside the development area, ensuring long-term sealing stability
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 ensures effective control of toner discharge outside the development area, achieving long-term stable sealing with a simple construction by guiding toner retained on the sleeve's peripheral surface back into the development area.
Implementation Method 1
a magnetic sealing member arranged on an axial end of the development sleeve across a gap from the peripheral surface of the development sleeve, the magnetic sealing member serving to confine the developer by means of a magnetic field formed in the gap from the fixed magnet roller
Implementation Method 2
The fixed magnet roller is formed so that the magnetic force created by the plurality of magnetic poles acts from the outer side to the inner side of the development sleeve in the axial direction
Data Source
AI summary
A developing device is disclosed which includes a fixed magnet roller 25 having a plurality of magnetic poles, a development roller 27 having a development sleeve 26 that is supported axially with the ability to rotate freely, and a magnetic sealing member 29 arranged at the end of the longitudinal direction X of the development sleeve 26. Further, the length of each of the plurality of magnetic poles not facing the magnetic sealing member 29 (in other words, the development pole S1, lead-in pole N1, and blade pole N3) of the fixed magnet roller 25 are shorter than the length of each of the plurality of magnetic poles facing the magnetic sealing member 29. Accordingly, the magnetic toner retained on the peripheral surface of the development sleeve 26 is guided to the development area side in the longitudinal direction X of the development sleeve 26.