Image Forming Apparatus Development Roller Voltage Inversion
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Solution Overview
Problem
Conventional image forming apparatuses face challenges in removing foreign bodies, such as softly-aggregated toner and external additives, from the contact place between the development roller and the regulation blade, which can lead to print defects like white streaks.
Innovation Solution
The image forming apparatus controls the rotation direction and voltage relationship between the development roller and the regulation blade after image formation, reversing the voltage magnitudes and rotating the development roller in both forward and reverse directions to enhance the flow of toner back to the accommodation part, facilitating the removal of foreign bodies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the development roller is periodically rotated in the reverse direction to remove foreign bodies, then shavings of the supply roller can be removed, but softly-aggregated toner and external additives cannot be sufficiently removed
Solution Approach 1:
The invention changes the electrical parameters (voltage magnitudes and polarity) during reverse rotation to enhance the removal of softly-aggregated toner. By applying a regulating voltage with reversed polarity and increased magnitude compared to normal development, the invention creates stronger electrostatic forces that effectively remove aggregated toner and external additives from the contact place between the development roller and regulation blade.
Solution Approach 2:
The invention implements periodic reverse rotation of the development roller at predetermined intervals during image formation. This periodic action allows the system to maintain normal development operation for productivity while periodically interrupting to perform foreign body removal, thus balancing both productivity and reliability requirements.
2Reliability
If the development roller rotates in the forward direction with inverted voltage relationship, then toner flow back to accommodation part increases removing softly-aggregated toner, but additional control complexity is introduced
Solution Approach 1:
The voltage controller is designed to perform multiple functions: normal development voltage control during image formation and enhanced foreign body removal voltage control during reverse rotation. By making the voltage controller multi-functional, the invention avoids adding separate control systems, thus managing complexity while achieving effective foreign body removal through inverted voltage relationships.
Solution Approach 2:
The invention combines the foreign body removal function with the existing development voltage control system. By merging the voltage control for normal operation and foreign body removal into a single control mechanism that adjusts voltage magnitudes and polarity based on operation mode, the invention reduces overall system complexity while maintaining effective foreign body removal capability.
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 approach effectively removes foreign bodies and prevents toner discharge, thereby reducing print defects and maintaining image quality over a larger number of printed pages.
Implementation Method 1
the voltage controller controls a development voltage applied to the developer carrier and a regulating voltage applied to the regulating member... in a state where the magnitude relationship between the development voltage and the regulating voltage is inverted from that during the image formation
Data Source
AI summary
An image forming apparatus executes an image formation process through which a developer image is formed on an image carrier by developing an electrostatic latent image while rotating a developer carrier in a forward direction, a voltage controller controls development and regulating voltages after the image formation process such that a magnitude relationship between the development regulating voltages becomes inverted from that during the image formation process, and after finishing the image formation process, in a state where the magnitude relationship between the development and regulating voltages is inverted from that during the image formation, the drive controller rotates the developer carrier in the forward direction for a prescribed period, and afterwards rotates the developer carrier in a reverse direction for another prescribed period.