Metal Transfer Rollers in Electrophotographic Apparatus
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Solution Overview
Problem
Conventional electrophotographic color image forming apparatuses experience transfer defects and image jitter due to increased pressure and irregular impact between photosensitive media and intermediate transfer belts, and incur higher fabrication costs and accuracy issues with the use of soft, elastic transfer rollers.
Innovation Solution
The apparatus features a design where the transfer nip is formed between a photosensitive medium and a circulating belt without pressing the two together, using metal transfer rollers and optimizing belt and roller geometries to reduce pressure and impact, allowing for a wider transfer nip and improved image transferring efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If soft rollers made of elastic material are used as transfer rollers to increase the width of the transfer nip, then the transfer nip width is improved, but the pressure between photosensitive media and intermediate transfer belt increases causing transfer defects and image jitter
Solution Approach 1:
The patent changes the material parameter of the transfer roller from elastic material (rubber) to non-elastic material (metal), fundamentally altering the interaction mechanism. This parameter change allows the transfer nip to be formed without pressing the photosensitive medium against the roller, thereby reducing pressure and preventing transfer defects while maintaining adequate transfer nip width through geometric design of the belt and roller arrangement.
2Area of moving object
If soft rollers made of elastic material are used as transfer rollers to increase the width of the transfer nip, then the transfer nip width is improved, but the fabrication costs increase and size accuracy maintenance becomes difficult
Solution Approach 1:
The patent changes the material parameter from elastic to non-elastic, which fundamentally improves manufacturability. Metal rollers are easier to fabricate with precise size accuracy compared to elastic materials, reducing both fabrication costs and maintenance requirements while achieving the same functional result through geometric optimization of the belt and roller configuration.
3Productivity
If pressure between photosensitive media and intermediate transfer belt is increased to improve transfer, then transfer efficiency is improved, but irregular impact increases causing transfer defects
Solution Approach 1:
The patent replaces the mechanical pressing system with a geometric configuration system. Instead of using elastic rollers to mechanically press the photosensitive medium against the belt, the invention uses the geometric arrangement of the belt and non-elastic rollers to create a transfer nip through their relative positions and dimensions, eliminating the need for pressing force while maintaining transfer efficiency.
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 image transferring efficiency, reduces transfer defects and image jitter, lowers fabrication costs by using metal rollers, and simplifies size accuracy maintenance.
Implementation Method 1
when a length of the belt between two neighboring transfer nips is B and a distance between a pair of neighboring photosensitive media is C, B is larger than C, and when respective virtual lines connecting centers of the pair of photosensitive media and centers of corresponding transfer rollers are TP lines and a virtual line connecting the centers of the pair of neighboring photosensitive media is a PP line, a pair of neighboring TP lines do not cross the PP line at right angles, and are slanted toward the same side to cross the PP line
Data Source
AI summary
An electrophotographic color image forming apparatus, having: a plurality of photosensitive media; a plurality of transfer rollers respectively facing the plurality of photosensitive media; and a belt disposed between the photosensitive media and the transfer rollers and circulating while forming a plurality of transfer nips. When a length of the belt between two neighboring transfer nips is B and a distance between a pair of neighboring photosensitive media is C, B is larger than C, and when respective virtual lines connecting centers of the pair of photosensitive media and centers of corresponding transfer rollers are TP lines and a virtual line connecting the centers of the pair of neighboring photosensitive media is PP line, a pair of neighboring TP lines do not cross the PP line at right angles, and are slanted toward the same side to cross the PP line.