Fusing Pressing Roller Hardness for Belt Wrinkle Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional endless belt type fusing units in image forming apparatuses suffer from wrinkling and damage of the fusing pressing belt due to uneven contact pressure and belt bias, leading to reduced lifespan and printing efficiency.
Innovation Solution
The fusing unit design includes pressing rollers with a surface hardness greater than or equal to the heating roller, along with a supporting unit that guides the belt bias and incorporates a wearing prevention plate to prevent damage, ensuring a stable and uniform fusing nip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the pressing roller has lower surface hardness than the heating roller, then the pressing roller deforms to form a fusing nip, but the fusing pressing belt becomes loose and wrinkles or folds
Solution Approach 1:
The patent changes the surface hardness parameter of the pressing roller to be greater than or equal to that of the heating roller. This parameter change prevents the pressing roller from deforming excessively, thereby maintaining the tautness and shape of the fusing pressing belt while still forming an effective fusing nip through controlled elastic deformation.
Solution Approach 2:
The patent inverts the conventional hardness relationship between the pressing roller and heating roller. Instead of the pressing roller being softer to form the nip, the pressing roller is made harder (hP ≥ hH), and the nip formation is achieved through the interaction of both rollers rather than deformation of the pressing roller alone.
2Area of stationary object
If the fusing pressing belt is wider than the pressing rollers, then the contact surface is expanded for better fusing performance, but the belt end parts protrude and are damaged
Solution Approach 1:
The patent changes the surface hardness parameter of the pressing roller to prevent excessive deformation at the belt end parts. This parameter change allows the belt to maintain its shape and resist damage while still providing the beneficial wider contact surface area for improved fusing performance.
3Force
If the pressing roller is elastically biased toward the heating roller, then the fusing nip is formed through pressure, but the belt bias causes the belt to contact guiding units and wear
Solution Approach 1:
The patent changes the surface hardness parameter to reduce excessive deformation and belt bias, thereby reducing friction and wear on the belt while maintaining sufficient pressing force for effective fusing.
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 design enhances the durability and printing quality by preventing wrinkling and folding of the fusing pressing belt, maintaining its shape and reducing wear, thereby improving fusion stability and extending the belt's lifespan.
Implementation Method 1
Heat generated by the heating lamp 1 is conducted to the heating roller 3, heating a surface of the heating roller 3
Implementation Method 2
The first and the second pressing rollers 5 and 7 rotatably support the fusing pressing belt 9 and cause the fusing pressing belt 9 to come into partial contact with the heating roller 3 or the supplied printable medium 10. The first pressing roller 5 rotates and is elastically biased toward the heating roller 3 by an elastic member (not shown) to press the heating roller 3.
Data Source
AI summary
A fusing unit provided in a printing path of an image forming apparatus to fuse an image transferred onto a printable medium, the fusing unit including a heat source; a heating roller of which a surface is heated by heat generated by the heat source; a plurality of pressing rollers which is provided opposite to the heating roller and presses a supplied printable medium in cooperation with the heating roller; a fusing pressing belt which is wound on the plurality of pressing rollers and forms a fusing nip contacting with the heating roller; and a supporting unit which rotatably supports the plurality of pressing rollers and guides the fusing pressing belt, a surface hardness hP of at least one of the plurality of pressing rollers is greater than or equal to a surface hardness hH of the heating roller.