Charging Member Voltage Control for Image Forming Apparatus
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Solution Overview
Problem
Existing image forming apparatuses face challenges in efficiently setting voltages for charging members across varying environmental temperatures, leading to increased downtime due to frequent switching between constant voltage control and discharge current control.
Innovation Solution
An image forming apparatus with a controller that adjusts the voltage applied to the charging member based on temperature differences, using a combination of direct-current and alternating-current voltages, and correction values to maintain optimal discharge current and reduce downtime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If discharge current control is performed every time environmental temperature changes, then appropriate voltage setting is achieved, but downtime increases
Solution Approach 1:
The system performs preliminary voltage setting based on temperature thresholds before actual image formation. When temperature changes are detected, the controller proactively adjusts the voltage setting in advance, ensuring optimal charging performance is maintained without waiting for performance degradation to occur.
Solution Approach 2:
The system continuously monitors environmental temperature and uses this feedback to dynamically adjust voltage settings. The controller compares current temperature against stored threshold values and automatically modifies operating parameters, creating a closed-loop control system that maintains optimal performance while minimizing interruptions.
2Loss of energy
If constant voltage control is used, then power consumption is reduced, but charging performance becomes unstable in varying temperatures
Solution Approach 1:
The system dynamically switches between constant voltage control and discharge current control modes based on real-time temperature conditions. In stable temperature environments, constant voltage control is used to minimize power consumption. When temperature fluctuations are detected, the system transitions to discharge current control to maintain charging performance stability, thus adapting to changing conditions optimally.
Solution Approach 2:
The controller changes the operating parameter (voltage or current control mode) based on temperature conditions. By monitoring temperature and adjusting the control parameter accordingly, the system maintains optimal charging performance across varying environmental conditions while minimizing unnecessary power consumption during stable periods.
3Reliability
If discharge current amount is increased, then charging performance stabilizes, but wear of photosensitive drum increases
Solution Approach 1:
The system changes the discharge current parameter dynamically based on temperature conditions. In high temperature environments, the controller increases the discharge current amount to maintain stable charging performance. In normal temperature conditions, it uses lower discharge current to minimize photosensitive drum wear, thus adapting the parameter to balance performance and durability.
Solution Approach 2:
The discharge current control is made dynamic rather than static. The system continuously monitors temperature and adjusts the discharge current amount in real-time, increasing it only when necessary to maintain performance stability and reducing it during normal conditions to preserve drum life, creating a flexible control strategy that balances competing requirements.
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 allows for efficient voltage setting and reduced downtime by dynamically adjusting the voltage based on environmental temperature fluctuations, ensuring stable charging performance while minimizing wear on the photosensitive drum.
Implementation Method 1
corona charging, which is non-contact charging in which corona generated by applying a high voltage to a thin corona discharge wire acts on the surface of the photosensitive drum to charge the photosensitive drum
Implementation Method 2
a voltage is applied to the charging member to charge the photosensitive drum... discharge current flowing between the charging member and the photosensitive drum
Implementation Method 3
a temperature detector configured to detect an environmental temperature
Implementation Method 4
a resistive load current flowing through a resistive load between the charging member and the photosensitive drum, a capacitive load current flowing through a capacitive load between the charging member and the photosensitive drum, and a discharge current flowing between the charging member and the photosensitive drum
Data Source
AI summary
Third control of controlling a voltage application portion to apply, to a charging member, a voltage obtained by offsetting a first correction value with respect to a value of a voltage previously applied to the charging member is performed in a case where an absolute value of a difference is lower than a predetermined threshold and first control is previously performed, and fourth control of controlling the voltage application portion to apply, to the charging member, a voltage obtained by offsetting a second correction value with respect to a value of a voltage previously applied to the charging member is performed in a case where the absolute value of the difference is lower than the predetermined threshold and second control is previously performed.