Wet-Type Developing Device Charger Configuration for Discharge Stability
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Solution Overview
Problem
Conventional wet-type image forming apparatuses face issues with toner adhesion to developing rollers, leading to failed cleaning processes due to uneven discharge characteristics of static and neutralizing chargers, resulting in image noise and streaks.
Innovation Solution
The use of corotron chargers with distinct sectional configurations and lengths for both static and neutralizing units, where the neutralizing unit has a lower voltage-current characteristic than the static unit, allows for stable discharge and extended adjustable range of flow-in current, improving cleaning performance and image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the neutralizing charger has the same configuration as the static charger, then the discharge characteristic is high, but the discharge becomes unstable and uneven
Solution Approach 1:
The patent applies different configurations to the static charger and neutralizing charger. Specifically, the neutralizing charger is designed with a different wire diameter, length, or spacing compared to the static charger, creating local quality differences that optimize each charger's discharge characteristics for its specific function while maintaining overall system reliability.
2Reliability
If the applied voltage to the wire is increased to ensure stable discharge, then discharge stability improves, but leakage initiation occurs
Solution Approach 1:
The patent changes physical parameters of the charger configuration, such as wire diameter, wire length, or spacing between wire and photoconductor surface. These parameter changes allow the system to achieve stable discharge at lower voltages, preventing leakage while maintaining discharge stability. For example, increasing wire diameter or adjusting spacing can modify the electric field distribution to prevent breakdown.
3Reliability
If the flow-in current from the static charger is increased to ensure adequate charging, then charging performance improves, but the adjustable range of flow-in current is restricted
Solution Approach 1:
The patent introduces adjustable parameters to the charger configuration, such as variable voltage control, adjustable wire spacing, or selectable wire configurations. These dynamic elements allow the flow-in current to be adjusted across a wide range while maintaining adequate charging performance, enabling adaptation to different operating conditions and toner types.
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 configuration enhances the settable range of flow-in current, suppresses image noise and failed cleaning, and stabilizes the neutralization process, ensuring effective toner removal and improved image forming efficiency.
Implementation Method 1
The charging unit is configured to charge the developer on the developer carrier by discharge
Implementation Method 2
The neutralizing unit is configured to neutralize the electric charge of the developer after the development by discharge
Data Source
AI summary
A wet-type developing device and a wet-type image forming apparatus each employ a developer including a carrier liquid and toner particles dispersed in the carrier liquid. A charging unit is applied with positive voltage. A neutralizing unit is applied with negative voltage. The charging unit and the neutralizing unit are made different from each other in one of a sectional configuration and a length to a developer carrier such that an absolute value of a voltage-current characteristic of the neutralizing unit becomes smaller than an absolute value of a voltage-current characteristic of the neutralizing unit including a constituent element equal to a constituent element of the charging unit.