Fixing Device with Dynamic Guide Angles for Sheet Crease Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image forming apparatuses face issues with creases in sheets, particularly in envelopes and large sheets of plain paper, due to velocity differences across the fixing device, leading to envelope creases and sheet back curls during double-sided printing.
Innovation Solution
The fixing device incorporates a pressure rotator, pressure plate, pressing force adjuster, entrance guide, exit guide, and transmission to adjust the pressing force and guide angles, ensuring synchronized entry and exit of sheets to prevent creases by optimizing the nip geometry and guide angles based on the type of paper.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the fixing device heats and presses the sheet to fix the image, then the image fixing quality is improved, but creases are generated in the sheet
Solution Approach 1:
The patent applies the dynamics principle by making the guide members movable rather than fixed. The entrance guide member and exit guide member can adjust their positions and angles dynamically based on the type of recording medium being processed. This allows the system to adapt the guiding geometry to different sheet characteristics (envelopes vs. plain paper), optimizing both image fixing quality and crease prevention for each medium type.
2Manufacturing precision
If the pressing force is increased to improve image fixing, then the image quality is improved, but sheet back curl and creases worsen
Solution Approach 1:
The patent applies parameter changes by adjusting multiple parameters simultaneously: pressing force, entrance guide angle, and exit guide angle. The control unit modifies these parameters based on the detected recording medium type. For envelopes, it uses lower pressing force with specific guide angles, while for plain paper, it applies higher pressing force with different guide angles, thereby optimizing image fixing while preventing sheet back curl and creases for each medium.
3Device complexity
If the fixing device uses a fixed guide configuration, then the device complexity is reduced, but it cannot prevent creases in different sheet types
Solution Approach 1:
The patent applies universality by designing a multi-functional guide system that can serve different purposes for different recording medium types. The same entrance guide member and exit guide member structure is used for both envelopes and plain paper, but their positions and angles are adjusted based on the medium type. This allows a single device configuration to handle multiple functions: preventing envelope creases and preventing sheet back curl, without requiring separate dedicated guide systems for each medium type.
Data Source
AI summary
A fixing device includes a fixing rotator, a pressure rotator, a pressure plate, a pressing force, an entrance guide, an exit guide, and a transmission. The pressure rotator presses the fixing rotator to form a nip between the fixing rotator and the pressure rotator. The pressure plate rotates about a fulcrum to press the pressure rotator. The pressing force adjuster adjusts a pressing force of the pressure rotator. The entrance guide guides a recording medium entering the nip. The exit guide guides the recording medium ejected from the nip. The transmission transmits a displacement of the pressure plate to the entrance guide and the exit guide.