Primary Transfer Roller Elastic Layer Hardness Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrophotographic image forming apparatuses face challenges in achieving optimal transfer performance due to insufficient contact area between the image bearing member and the belt, leading to inefficiencies in toner transfer.
Innovation Solution
The apparatus includes a rotatable image bearing member and a movable endless belt with a transfer member having a core metal and an elastic layer, where the transfer member is positioned to create a larger contact area by being urged towards the image bearing member, with specific hardness and thickness settings to enhance transfer efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the transfer member is urged toward the image bearing member to increase the wound area, then the transfer performance is improved, but the adhesion forces between toner and image bearing member increase making transfer more difficult
Solution Approach 1:
The patent applies parameter changes by carefully controlling the hardness (40-85° Asker-C) and thickness (less than 2.0 mm) of the elastic layer on the transfer member. These parameter optimizations allow the elastic layer to provide sufficient compliance for forming an appropriate wound area that improves transfer performance, while preventing excessive adhesion forces that would hinder toner release from the image bearing member.
2Shape
If a thicker elastic layer is used on the transfer member, then the wound area formation is improved, but the transfer precision and character quality deteriorate
Solution Approach 1:
The patent resolves this contradiction through parameter changes by specifying that the elastic layer thickness must be less than 2.0 mm. This thickness constraint ensures that the elastic layer is sufficiently thin to maintain transfer precision and character quality, while still being thick enough to provide the compliance necessary for forming an appropriate wound area between the belt and image bearing member.
3Stability of the object's composition
If the elastic layer hardness is increased, then the structural stability is improved, but the ability to form appropriate wound area decreases
Solution Approach 1:
The patent applies parameter changes by defining the elastic layer hardness within the range of 40-85° Asker-C. This optimized hardness range provides the ideal balance: the elastic layer is soft enough to deform and form an appropriate wound area that increases contact between the belt and image bearing member, while maintaining sufficient structural stability to support the transfer function and maintain operational reliability.
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 increases the transfer performance by reducing adhesion forces between the toner and the image bearing member, allowing for more efficient toner transfer and minimizing image defects, while maintaining stable operation and character quality.
Implementation Method 1
The transfer member includes a core metal and an elastic layer coating the outer circumference of the core metal. The elastic layer has a thickness of less than 2.0 mm and an Asker-C hardness of 40° or higher and 85° or lower. The transfer member is urged toward the image bearing member to push the image bearing member via the belt to form a region where the belt winds around the image bearing member.
Data Source
AI summary
A primary transfer roller is disposed upstream or downstream from the center of rotation of a photosensitive drum in the moving direction of an intermediate transfer belt. The primary transfer roller includes a core metal and an elastic layer coating the outer circumference of the core metal and having a thickness of less than 2.0 mm. The primary transfer roller has an Asker-C hardness of 40° or higher and 85° or lower.