Image Forming Apparatus Voltage Cascade for Transformer Load Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image forming apparatuses face challenges in reducing costs while preventing image defects caused by excessive load on transformers due to voltage control configurations, leading to higher transformer costs and sizes, and wear at contact points between members involved in the development process.
Innovation Solution
An image forming apparatus with a configuration that includes multiple power sources generating voltages with controlled potential differences, using a transformer to generate a first voltage, a second power source to generate a second voltage from the first, and a third power source to generate a third voltage, with a controller managing these differences to minimize wear and prevent defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If multiple voltages are generated from one high-voltage circuit by voltage divider control, then circuit cost is reduced, but transformer load becomes excessive leading to higher transformer cost and size
Solution Approach 1:
The patent applies dynamics by making the voltage application state changeable - the developing member voltage is dynamically adjusted between a first voltage during image formation and a second voltage (lower than first voltage) during contact between contacting members. This dynamic voltage adjustment allows the transformer to operate at lower power during contact periods, reducing overall transformer load and allowing use of a smaller, less expensive transformer while maintaining proper voltage levels during actual image formation.
Solution Approach 2:
The patent implements periodic action by alternating between two operational states: image formation mode (where full voltage is applied to the developing member) and contact mode (where reduced voltage is applied). The controller periodically switches between these states based on whether the developing member is contacting the photosensitive member or contacting other members, allowing the transformer to operate at reduced capacity during contact periods and full capacity only when needed for image formation.
2Power
If voltage is controlled not to be output from one high-voltage circuit, then transformer capacity can be reduced, but image defects occur due to contact portions between members
Solution Approach 1:
The patent applies local quality by differentiating voltage application based on the specific contact situation - when contacting members (such as the developing blade contacting the developing roller) are in contact during the developing process, a lower second voltage is applied to prevent discharge and image defects at these specific contact portions, while during normal image formation, the full first voltage is applied to ensure proper image quality. This localized voltage control prevents image defects without requiring excessive transformer capacity.
Solution Approach 2:
The patent implements parameter changes by varying the voltage parameter applied to the developing member based on operational state. The controller changes the voltage from the first voltage (higher) during image formation to the second voltage (lower) during contact between contacting members. This parameter adjustment prevents harmful discharges at contact portions that would cause image defects like white spots or streaks, while maintaining sufficient voltage for proper image formation when contacts are not occurring.
3Manufacturing precision
If developing blade contacts developing roller to even out toner, then toner distribution is improved, but wear occurs at contact portions leading to image defects
Solution Approach 1:
The patent applies beforehand cushioning by reducing the voltage applied to the developing member during contact periods between the developing blade and developing roller. By lowering the voltage to the second voltage level during these contact portions, the electrical stress and discharge at the contact interface are reduced, which cushions against wear and deterioration of the contacting members. This protective measure is applied in advance during contact periods to prevent image defects caused by wear, while still allowing the blade to perform its toner-evening function mechanically.
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 effectively reduces transformer load, minimizes wear at contact points, and prevents image defects by controlling voltage differences during contact and separation states, enhancing durability and reducing costs.
Implementation Method 1
a first power source including a transformer and configured to generate a first voltage
Implementation Method 2
a second power source configured to generate a second voltage, from the first voltage, and to apply the second voltage to the first contacting member
Implementation Method 3
a third power source configured to generate a third voltage from the second voltage generated by the second power source and to apply the third voltage to the developing member
Data Source
AI summary
An image forming apparatus includes a photosensitive member, a charging member, a developing member, a contacting member contacting the developing member, and first to third power sources. The first power source generates a first voltage and applies it to the charging member. The second power source generates a second voltage, lower than the first voltage, from the first voltage and applies it to the contacting member. The third power source generates a third voltage, lower than the second voltage, from the second voltage and applies it to the developing member.