Image Forming Transfer Belt Speed Differential to Prevent Belt Waving
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The use of low-hardness transfer rollers in image forming apparatuses leads to permanent deformation and waving of the transfer belt, resulting in image deterioration and toner scattering due to electric discharge, especially in belt transfer devices with two stretching rollers.
Innovation Solution
The image forming apparatus employs a downstream roller with a higher surface speed than the inner peripheral speed of the second belt to stabilize the transfer belt surface, reducing waving and preventing permanent deformation of the low-hardness transfer roller.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a low-hardness transfer roller is used to suppress image deterioration, then image quality is improved, but the transfer roller undergoes permanent deformation and causes belt waving
Solution Approach 1:
The patent changes the operational parameters by controlling the speed relationship between the downstream roller and the transfer belt. By making the downstream roller's surface speed higher than the belt's inner peripheral speed, the system creates a speed differential that prevents belt waving without requiring changes to the transfer roller's material properties or structural design.
2Stability of the object's composition
If the transfer belt is stretched tightly to prevent waving, then belt stability is improved, but the low-hardness transfer roller undergoes permanent deformation
Solution Approach 1:
The patent replaces the mechanical tensioning system with a speed-controlled system. Instead of relying on mechanical stretching forces to maintain belt stability, the invention uses differential speed control between the downstream roller and transfer belt to achieve the same stabilizing effect without imposing excessive mechanical loads on the transfer roller.
3Device complexity
If a simple two-roller stretching mechanism is used for cost reduction, then device complexity is reduced, but it becomes difficult to provide tension alleviation mechanisms
Solution Approach 1:
The patent implements a self-regulating system where the speed differential between the downstream roller and transfer belt automatically adjusts to maintain optimal belt tension. The system self-adapts to different operating conditions through speed control without requiring additional tension adjustment mechanisms or complex control systems.
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 effectively suppresses belt waving and prevents permanent deformation, maintaining image quality by minimizing toner scattering and electric discharge, while allowing for cost-effective and space-efficient belt tensioning mechanisms.
Implementation Method 1
a surface speed of the downstream roller is set so as to become higher than an inner peripheral surface speed of the second belt
Implementation Method 2
the low-hardness member is elastically deformed in the portion where the transfer belt is extended and stretched
Implementation Method 3
The toner image on the intermediary transfer belt is electrostatically transferred onto the recording material by nipping the recording material in a transfer portion
Data Source
AI summary
An image forming apparatus includes an image bearing member, a first belt, a driving roller, a first driving source, an inner roller, a second belt, a transfer roller for nipping the first belt and the second belt and for transferring a toner image from the first belt onto the recording material, a downstream roller provided to contact an inner peripheral surface of the second belt on a side downstream of the transfer roller with respect to a recording material conveying direction and for forming a surface, on which the recording material is conveyed, between itself and the transfer roller, and a second driving source for rotationally driving the downstream roller. During transfer in which the toner image is transferred onto the recording material, a surface speed of the downstream roller is set to become higher than an inner peripheral surface speed of the second belt.