Separator Recesses for Image Fixing Nip Friction
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Solution Overview
Problem
Existing image forming apparatuses face issues with the separation of recording media from rotators, leading to gloss streaks and jamming due to uneven pressure and thermal expansion, which affects the quality of the toner image.
Innovation Solution
A separation device with a separator plate featuring a plurality of obliquely extending recesses is used downstream from the fixing nip, reducing friction and ensuring even contact with the recording medium, thereby preventing gloss streaks and jamming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a smooth separator surface is used to separate the recording medium from the rotator, then the separation function is achieved, but gloss streaks occur on the toner image due to uneven pressure and thermal expansion
Solution Approach 1:
The separator surface is designed with local variations in texture through recesses and protrusions. The recesses create localized contact points that distribute pressure evenly, while the protrusions provide thermal expansion compensation. This local quality variation allows the separator to maintain reliable separation function while preventing gloss streaks on the toner image.
Solution Approach 2:
The recesses on the separator surface create curved contact interfaces with the recording medium. These curved surfaces distribute contact pressure more uniformly compared to flat surfaces, reducing localized high-pressure points that cause gloss streaks. The curvature also accommodates thermal expansion of the rotator more effectively.
2Object-affected harmful factors
If the separator contacts the recording medium uniformly to prevent gloss streaks, then image quality is improved, but friction increases causing jamming
Solution Approach 1:
The separator surface is segmented into multiple recesses and protrusions rather than being a continuous smooth surface. This segmentation reduces the total contact area between the separator and recording medium, lowering friction and preventing jamming. Meanwhile, the distributed contact points maintain uniform pressure distribution to prevent gloss streaks.
Solution Approach 2:
The surface parameters of the separator are changed by introducing recesses with specific depths, widths, and spacing. These parameter changes optimize the balance between friction reduction and uniform pressure distribution. The recesses create controlled contact zones that maintain image quality while reducing overall friction to prevent jamming.
3Reliability
If the separator is designed with complex recess patterns to prevent gloss streaks and jamming, then image quality and reliability are improved, but device complexity increases
Solution Approach 1:
The separator incorporates a porous or micro-structured surface with recesses that can be formed through relatively simple manufacturing processes. This porous-like structure provides the necessary complexity for preventing gloss streaks and jamming without requiring complex multi-component designs. The recesses can be created using standard machining or molding techniques, keeping device complexity manageable.
Solution Approach 2:
The separator combines multiple functions into a single component: separation, pressure distribution, and thermal expansion compensation. The recess pattern integrates these functions rather than requiring separate mechanisms. This merging approach improves reliability while avoiding the increased complexity that would result from multiple separate components.
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 separates the recording medium from the rotator, reducing friction and preventing gloss streaks and jamming, thereby improving the quality and integrity of the toner image.
Implementation Method 1
a plurality of recesses disposed on the front end of the separator at least in a conveyance span on the separator where the recording medium is conveyed
Data Source
AI summary
A separation device separates a recording medium ejected from a fixing nip formed between a first rotator and a second rotator from the first rotator. The separation device includes a separator including a front end disposed opposite the fixing nip and the recording medium and a plurality of recesses disposed on the front end of the separator at least in a conveyance span on the separator where the recording medium is conveyed. The plurality of recesses includes a first recess extending in a first extension line that is oblique relative to a recording medium conveyance direction and a second recess adjacent to the first recess and extending in a second extension line that is oblique relative to the recording medium conveyance direction. The second extension line overlaps the first extension line in a direction perpendicular to the recording medium conveyance direction to define an overlap span.