Charge Roller Damper for Consistent Electrophotographic Charging
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Solution Overview
Problem
Print defects occur in electrophotographic printers due to the charge roller moving away from the photo imaging plate at a seam, causing inconsistent charging and resulting in defects within the print zone.
Innovation Solution
Incorporating a compressible movement damper to maintain the charge roller within an upper threshold distance of the printer surface, preventing movement away from the surface and ensuring consistent charging by using a combination of polyurethane foam or other shock absorbers to resist displacement without impeding rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the charge roller is allowed to move freely during operation, then the printer can accommodate surface movement, but the charge roller moves away from the photo imaging plate at seams causing inconsistent charging and print defects
Solution Approach 1:
The patent introduces a damper that changes the mechanical parameters of the charge roller assembly by providing controlled resistance to movement. The damper modifies the roller's response to seam movements, preventing excessive displacement while maintaining consistent charging contact with the photo imaging plate throughout the rotation cycle.
Solution Approach 2:
The damper acts as an intermediary element between the charge roller and the photo imaging plate. It mediates the interaction by absorbing and dampening the effects of seam movements, thereby maintaining stable charging conditions without requiring the roller to be rigidly fixed.
2Manufacturing precision
If the charge roller is rigidly fixed to prevent movement, then charging consistency is maintained, but the roller cannot accommodate surface movement and may cause defects
Solution Approach 1:
The patent transitions from a static, rigid fixation to a dynamic system where the charge roller can move within controlled limits. The damper enables the roller to adapt its position dynamically in response to seam movements while maintaining sufficient contact for consistent charging, thus achieving both flexibility and precision.
3Manufacturing precision
If a damper is introduced to reduce roller movement, then charging consistency improves, but the device complexity increases
Solution Approach 1:
The patent employs a simple damper component that can be implemented using readily available materials such as rubber or foam. This inexpensive element provides effective movement damping without requiring complex mechanical structures, thereby improving charging consistency while adding minimal complexity to the overall device.
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
The solution effectively reduces print defects by maintaining consistent charging across the printer surface, ensuring the charge roller and bias roller remain within the necessary contact distance, thereby improving image quality and reducing defects.
Implementation Method 1
a compressible movement damper to reduce movement of the charge roller in response to the photo imaging plate being moved
Implementation Method 2
a compressible movement damper to reduce movement of the charge roller
Implementation Method 3
Charge rollers are used to apply the uniform charge to the electrophotographic surface prior to drawing the latent image
Data Source
AI summary
Apparatus, printers, and charge roller assemblies are disclosed. An example apparatus includes a roller to charge a printer surface when closer to the printer surface than an upper threshold, and a damper to reduce movement of the roller and to keep the roller closer to the printer surface than the upper threshold.