Variable Bias Control for Intermediate Transfer Belt Cleaning
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Solution Overview
Problem
Existing image forming apparatuses using intermediate transfer type struggle with uneven cleaning of toner residues on the intermediate transfer belt due to varying types of recording materials, leading to faulty cleaning, especially with embossed papers where surface irregularities cause uneven toner distribution and low transfer efficiency.
Innovation Solution
The implementation of controlling means to variably control the bias condition applied to electrostatic fur brush cleaning means based on the type of recording material, ensuring optimal cleaning by adjusting bias voltages applied to upstream and downstream fur brushes to match the charged state of residual toners, thereby preventing toner reversal and improving transfer efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single bias polarity is applied to fur brush cleaning means, then the cleaning process is simple, but all untransferred toners cannot be collected due to mixed polarity toners
Solution Approach 1:
The cleaning means is divided into multiple fur brushes (first and second fur brushes) with independent bias control. Each fur brush can be applied with different bias polarities (positive or negative) depending on the toner polarity that needs to be collected, enabling complete collection of mixed polarity toners while maintaining manageable system complexity through modular design
Solution Approach 2:
The bias voltage applied to each fur brush is made variable and controllable based on the type of recording material. The control unit dynamically adjusts the bias polarity and voltage magnitude according to detected material characteristics, allowing optimal cleaning performance across different paper types while adapting to changing conditions
2Reliability
If bias voltage is increased to remove more untransferred toner, then cleaning effectiveness improves, but toner reversal occurs and discharged toner affects image quality
Solution Approach 1:
The bias voltage parameters (polarity and magnitude) are changed according to the type of recording material detected. By adjusting these parameters dynamically, the system achieves effective toner collection without excessive voltage that would cause toner reversal or discharge, thereby eliminating harmful effects while maintaining cleaning effectiveness
Solution Approach 2:
The control unit detects the type of recording material and uses this information to feedback-adjust the bias voltage applied to the fur brushes. This closed-loop control ensures that the bias voltage remains within optimal ranges to prevent toner reversal and discharge while effectively collecting untransferred toners
3Productivity
If transfer bias is adjusted for salient portions, then transfer efficiency improves, but untransferred toner increases in indentation portions
Solution Approach 1:
Different bias voltages are applied to different fur brushes based on the local requirements of different paper surfaces. The control unit adjusts the bias voltage for each fur brush according to the specific characteristics of the recording material, ensuring optimal cleaning performance across both salient and indentation portions without requiring uniform treatment throughout
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 cleaning of the intermediate transfer belt regardless of the recording material type, minimizing toner reversal and maintaining image quality by optimizing bias settings for different paper surfaces, thus addressing the issue of uneven toner removal and transfer efficiency.
Implementation Method 1
a bias is applied to fur brush cleaning means to thereby electrostatically remove the residual toners
Data Source
AI summary
An image forming apparatus having an image bearing member rotatable and bearing a toner image thereon, a transferring apparatus for electrostatically transferring the toner image borne on the image bearing member to a recording material, a cleaning apparatus for electrostatically removing any toner not transferred to the recording material by the transferring apparatus but residual on the image bearing member from the image bearing member, a bias applying apparatus for applying a bias to the cleaning apparatus, and a controlling apparatus for variably controlling the bias condition of the bias applied to the cleaning apparatus by the bias applying apparatus, in accordance with the type of the recording material.