Variable Bias Cleaning Members for Residual Toner Removal
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Solution Overview
Problem
In image forming apparatuses using the electrophotographic printing method, continuous image formation leads to insufficient collection of untransferred residual toner despite the use of two cleaning members with different polarity biases, due to changes in electrical resistance and unequal amounts of toner adherence.
Innovation Solution
The implementation of controlling means to independently vary the bias conditions applied to the first and second cleaning members, allowing for optimal removal of toner of both positive and negative polarities by adjusting the bias based on adherence and resistance changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two cleaning members with fixed polarity biases are used to remove residual toner, then both positive and negative polarity toner can be collected, but collection efficiency deteriorates during continuous image formation
Solution Approach 1:
The patent applies dynamics by making the bias voltage applied to cleaning members variable rather than fixed. The controlling means adjusts the bias voltage in response to changes in electrical resistance of cleaning members during continuous operation, allowing the system to adapt to changing conditions and maintain effective toner collection throughout extended use
Solution Approach 2:
The patent implements parameter changes by modifying the bias voltage parameter based on the electrical resistance state of cleaning members. The controlling means detects resistance changes and adjusts the voltage parameter accordingly, ensuring optimal toner collection efficiency is maintained even as cleaning members accumulate toner and their resistance characteristics change over time
2Device complexity
If fixed bias voltages are applied to cleaning members, then simple control structure is maintained, but inability to adapt to resistance changes reduces cleaning effectiveness
Solution Approach 1:
The patent implements feedback by using the controlling means to monitor electrical resistance changes in cleaning members and adjust bias voltages in response. This closed-loop control ensures that cleaning effectiveness is maintained by adapting to real-time changes in cleaning member characteristics without requiring overly complex control architecture
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 solution ensures effective collection of untransferred residual toner, preventing slipping out and maintaining image quality during continuous image formation.
Implementation Method 1
a first power supply for applying a bias of the same polarity as the predetermined polarity to the first cleaning member; a second power supply for applying bias of a polarity opposite to the predetermined polarity to the second cleaning member
Data Source
AI summary
An image forming apparatus including an image bearing member bearing thereon a toner image charged to a predetermined polarity, a transferring device for electrostatically transferring the toner image borne on the image bearing member to a recording material, first and second cleaning members for electrostatically removing from the image bearing member any toner residual on the image bearing member when the toner image is transferred to the recording material, a first power supply for applying a bias of the same polarity as the predetermined polarity to the first cleaning member, a second power supply for applying a bias of a polarity opposite to the predetermined polarity to the second cleaning member, and a controller for variably controlling the condition of the bias applied to the first cleaning member and the condition of the bias applied to the second cleaning member independently of each other.