Transfer Device Cam Gap Control for Cardboard Impact Jitter
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Solution Overview
Problem
Conventional image forming apparatuses face issues with impact jitter and transfer errors when using cardboard as a recording medium, due to sudden increases in load on the image bearer, leading to suboptimal image quality.
Innovation Solution
An image transfer device with an engaging and disengaging mechanism using a cam system to adjust the gap between the image bearer and the transfer roller, applying different biases during the passage of an adjustment pattern and the recording medium, and controlling the cam positions to minimize load changes and maintain sufficient transfer pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the transfer roller maintains constant contact pressure with the image bearer, then image transfer quality is improved, but impact jitter occurs when cardboard enters the transfer nip
Solution Approach 1:
The transfer roller's contact pressure with the image bearer is made dynamic rather than constant. A cam mechanism converts rotational motion into periodic linear displacement, causing the transfer roller to periodically approach and recede from the image bearer. This dynamic adjustment reduces impact jitter when cardboard enters the transfer nip while maintaining sufficient transfer pressure for quality image transfer during normal operation.
Solution Approach 2:
The cam mechanism is positioned and timed to create a preliminary gap between the transfer roller and image bearer before cardboard enters the transfer nip. This preliminary action prevents the sharp load increase and impact jitter that would otherwise occur when thick recording media like cardboard enter the contact zone, while allowing normal transfer pressure to be applied subsequently.
2Object-affected harmful factors
If the transfer roller is disengaged from the image bearer to reduce load, then impact jitter is suppressed, but transfer pressure becomes insufficient causing transfer errors
Solution Approach 1:
The cam mechanism generates periodic action by converting continuous rotational motion into periodic linear displacement. The transfer roller periodically approaches the image bearer to apply transfer pressure and recedes to reduce load. This periodic cycle ensures sufficient transfer pressure is applied during the approach phase for accurate image transfer while reducing impact during the recession phase, thereby preventing both transfer errors and impact jitter.
3Reliability
If a cam mechanism is introduced to dynamically adjust the transfer nip, then impact jitter and transfer errors are reduced, but device complexity increases
Solution Approach 1:
The cam acts as an intermediary mechanism between the motor-driven rotation system and the transfer roller positioning system. It converts rotational motion into the required linear displacement pattern, providing a simple mechanical solution that avoids complex control systems, sensors, or actuators while achieving dynamic adjustment of the transfer nip to reduce impact jitter and maintain transfer consistency.
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 impact jitter and transfer errors, ensuring consistent and high-quality image transfer by dynamically adjusting the transfer nip pressure in response to varying recording medium thicknesses and types.
Implementation Method 1
An engaging and disengaging mechanism using a cam system to adjust the gap between the image bearer and the transfer roller
Implementation Method 2
subjecting the transfer roller to a biasing force of a spring that serves as a pressing device to press the transfer roller against the photoconductive member
Implementation Method 3
a transfer bias device to apply an image transfer bias transferring an image formed on the image bearer onto the recording medium conveyed and pinched at the transfer nip
Data Source
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AI summary
An image transfer system comprises an image bearer and an opposed member having a contact surface contacting a recording medium and opposed to a surface of the image bearer to form a transfer nip. A pressing device applies pressure to the transfer nip. An engaging and disengaging member engages and disengages the contact surface from the surface of the image bearer. A transfer bias device applies a transfer bias transferring an image formed on the image bearer onto the recording medium conveyed and pinched at the transfer nip. The image is composed of an adjustment pattern formed on a portion of the image bearer corresponding to an interval between recording mediums successively conveyed through the transfer nip. The engaging and disengaging device disengages the contact surface from the surface of the image bearer to form a gap therebetween when the adjustment pattern passes therethrough.