Image Forming Apparatus Charging Voltage Control
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Solution Overview
Problem
Inline color image forming apparatuses face challenges in maintaining favorable transferability and retransferability due to variations in the charged and exposed portion potentials of photosensitive drums with different degrees of wear, which are difficult to control independently when sharing a common power supply.
Innovation Solution
An image forming apparatus with a common transfer power supply and different charging power supplies for each unit, where a control unit adjusts the charging voltage and exposure amount based on the specific conditions of each image forming unit to maintain consistent potentials across units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a common power supply is used to apply high voltages to multiple primary transfer members, then the device complexity is reduced, but the manufacturing precision of transfer and retransfer contrasts deteriorates due to variations in photosensitive drum wear
Solution Approach 1:
The power supply system is segmented into a common transfer power supply and individual charging power supplies for each image forming unit. This segmentation allows the transfer voltage to be shared (reducing complexity) while enabling independent control of charging voltages (maintaining precision) for each photosensitive drum regardless of wear degree.
Solution Approach 2:
Different charging voltages are applied to different image forming units based on their specific conditions (photosensitive drum wear). The common transfer power supply provides uniform transfer voltage, while local variations in charging voltage compensate for differences in photosensitive drum characteristics, ensuring consistent transfer and retransfer contrasts across all units.
2Manufacturing precision
If different charging voltages are applied to each image forming unit to maintain consistent potentials, then the manufacturing precision of transfer contrasts is improved, but the device complexity increases
Solution Approach 1:
The transfer power supply is merged into a common unit that serves all image forming units, reducing the number of power supplies needed. Meanwhile, the charging power supplies remain separate to allow independent voltage adjustment. This combination strategy reduces overall system complexity while maintaining the ability to optimize each unit's charging voltage for consistent performance.
3Adaptability or versatility
If photosensitive drums with different degrees of wear are mounted on stations, then the adaptability of the apparatus is improved, but the reliability of transferability and retransferability deteriorates due to potential variations
Solution Approach 1:
The charging voltage parameter is changed for each image forming unit based on the wear degree of its photosensitive drum. By adjusting this electrical parameter, the system adapts to different drum conditions while maintaining reliable transfer and retransfer performance. The common transfer voltage combined with adjusted charging voltages compensates for wear-related potential variations.
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 ensures consistent transfer and retransfer contrasts across all stations, improving the reliability and quality of image formation while simplifying the apparatus by reducing variations in potential differences.
Implementation Method 1
a charging device configured to charge the image bearing member
Implementation Method 2
an exposure device configured to expose the image bearing members charged by the charging devices to form the latent images on the image bearing members
Implementation Method 3
a transfer device configured to transfer the developer image from the image bearing member to a transfer member
Data Source
AI summary
An image forming apparatus includes an exposure device configured to expose image bearing members charged by charging devices to form latent images on the image bearing members, and a control unit configured to, in ether one or both of an image forming unit A and an image forming unit B, adjust an amount of exposure by which the image bearing member is exposed and a charging voltage based on information about the image bearing members of the image forming units A and B. The control unit is configured to make the charging voltage and the amount of exposure in the image forming unit A different from the charging voltage and the amount of exposure in the image forming unit B.