Developing Member Metal Soap Supply Control for Image Defects
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Solution Overview
Problem
The use of metal soap in image forming apparatuses leads to image defects due to its transfer onto the charging roller, causing inadequate charging and increased torque, which is difficult to manage, especially in long-life cartridges.
Innovation Solution
An image forming apparatus with a control unit that executes a metal soap supply operation, including two modes: one for initial usage and another for later stages, where the metal soap is supplied with varying potential differences and amounts to prevent charging roller coverage and maintain low torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If metal soap is supplied to the photosensitive member surface to suppress adhesion of discharge products, then torque is reduced, but image defects occur due to charging roller coverage
Solution Approach 1:
The patent applies dynamics by changing the operational state of the developing member between two modes: in the first mode, the developing member rotates in the same direction as the photosensitive member to supply metal soap; in the second mode, it rotates in the opposite direction to prevent metal soap transfer to the charging roller. This dynamic reversal of rotation direction allows the system to adapt to different operational requirements and avoid image defects.
Solution Approach 2:
The patent implements periodic action by alternately switching between two operational modes for the developing member. The control unit periodically changes the rotation direction based on operational needs: one mode for metal soap supply and another mode for preventing charging roller coverage. This periodic switching ensures both torque reduction and prevention of image defects over time.
2Object-affected harmful factors
If metal soap is supplied from developer to photosensitive member, then discharge product adhesion is suppressed, but charging roller surface is covered causing inadequate charging
Solution Approach 1:
The patent uses dynamics by reversing the rotation direction of the developing member between two modes. In the first mode, rotation in the same direction as the photosensitive member enables metal soap supply. In the second mode, rotation in the opposite direction prevents metal soap from transferring to the charging roller, thus avoiding charging roller coverage while maintaining the benefit of suppressed discharge product adhesion.
Solution Approach 2:
The patent applies parameter changes by modifying the rotation direction parameter of the developing member. The control unit changes this parameter between two states: positive rotation for metal soap supply and negative rotation for preventing charging roller coverage. This parameter switching allows the system to control metal soap distribution and avoid harmful effects.
3Strength
If hardness of photosensitive member surface is increased for wear resistance, then wear resistance is improved, but coefficient of friction becomes high causing increased torque
Solution Approach 1:
The patent applies parameter changes by modifying the surface property parameter through metal soap coating. The metal soap forms a low-friction layer on the hard photosensitive member surface, changing the friction parameter without altering the hardness. This allows the system to maintain both wear resistance and low torque.
Solution Approach 2:
The patent uses composite materials by combining the hard photosensitive member surface with metal soap coating. The metal soap acts as a functional layer that provides low-friction properties while the underlying photosensitive member maintains its wear resistance. This composite structure resolves the contradiction between hardness and friction.
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 suppresses image defects and torque increases by optimizing metal soap distribution, ensuring consistent charging performance throughout the cartridge's life.
Implementation Method 1
a potential difference that is formed between the supply member and the developing member and causes an electrostatic force in a direction from the supply member to the developing member to act on the metal soap
Data Source
AI summary
An image forming apparatus comprising: an image bearing member, a developing member that forms a toner image with a toner including a metal soap having a polarity opposite to that of the toner, a supply member that supplies the toner to the developing member, and a control unit that executes a metal soap supply operation of supplying the metal soap from the developing member to the image bearing member when an operation other than the image forming operation is executed, wherein the metal soap supply operation includes a first mode and a second mode, and a potential difference between the supply member and the developing member, which causes an electrostatic force in the direction from the supply member to the developing member to act on the metal soap, is smaller in the metal soap supply operation in the second mode than in the first mode.