Fixing Device Separation Member Axial Movement Abrasion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electrographic image forming apparatuses, the continuous contact between the separation member and the fixing member leads to partial abrasion of the fixing member, reducing its releasability and causing toner offset, as the separation member wears down the same part of the fixing member, resulting in uneven abrasion and reduced lifespan.
Innovation Solution
A fixing device with a movement mechanism that moves the separation member along a rotation axis direction within a defined movement area, where the pressing load varies depending on the position, with lower pressure at the central position and higher pressure at the end positions, to distribute the contact time and prevent excessive abrasion of the fixing roller.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the separation member continuously contacts the same part of the fixing member, then the separation function is maintained, but the fixing member suffers partial abrasion and wear
Solution Approach 1:
The separation member is made movable along the rotation axis direction of the fixing member through a movement mechanism, allowing it to dynamically change its contact position rather than continuously contacting the same stationary point. This dynamic positioning distributes wear across different areas of the fixing member, extending its lifespan while maintaining separation functionality.
Solution Approach 2:
The contact interaction is extended from a single-point contact to a multi-position contact along the rotation axis direction. By introducing movement along the axial dimension, the separation member contacts different circumferential positions of the fixing member over time, distributing abrasion and preventing localized wear that would otherwise occur with static contact.
2Reliability
If the separation member is pressed against the fixing member with constant load, then separation effectiveness is maintained, but uneven abrasion occurs due to continuous contact at the same position
Solution Approach 1:
The pressing member is configured to vary the pressing load according to the position of the separation member along the rotation axis. When the separation member is at end positions of its movement range, the pressing load is increased to maintain effective separation. When at the central position, the pressing load is reduced. This dynamic load adjustment compensates for the changed contact geometry and maintains uniform abrasion distribution while preserving separation effectiveness.
Solution Approach 2:
The pressing load parameter is dynamically changed based on the separation member's position. The pressing member adjusts the magnitude of the pressing force according to the separation member's location along the rotation axis, increasing load at end positions and decreasing it at the central position. This parameter variation ensures consistent separation performance while distributing wear uniformly across the fixing member surface.
3Duration of action of stationary object
If a movement mechanism is added to move the separation member, then abrasion is distributed and lifespan is extended, but device complexity increases
Solution Approach 1:
The movement mechanism and pressing member are integrated into a unified structure. The pressing member simultaneously performs two functions: applying pressing force to the separation member and guiding its movement along the rotation axis direction. This merging of functions reduces the number of separate components needed compared to having an independent movement mechanism plus a separate pressing device, thereby reducing overall system complexity while achieving the desired abrasion distribution.
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 prevents excessive abrasion of the fixing roller, extends its lifespan, and maintains consistent releasability, thereby reducing toner offset and ensuring reliable image fixation.
Implementation Method 1
The fixing member rotates around a rotation axis extended in a rotation axis direction and fixes a toner image on a recording medium
Implementation Method 2
The separation member comes in contact with the fixing member and separates the recording medium from the fixing member
Implementation Method 3
The pressing member presses the separation member against the fixing member
Data Source
AI summary
A fixing device includes a fixing member, a separation member, a movement mechanism, and a pressing member. The fixing member rotates around a rotation axis extended in a rotation axis direction and fixes a toner image on a recording medium. The separation member comes in contact with the fixing member and separates the recording medium from the fixing member. The movement mechanism moves the separation member in the rotation axis direction and within a movement area. The pressing member presses the separation member against the fixing member. A pressing load of the separation member against the fixing member in a case where the separation member is located at a central position of the movement area is lower than a pressing load of the separation member against the fixing member in a case where the separation member is located at both end positions of the movement area.