Image Cartridge Roller Separation for Drum Contact Control
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Solution Overview
Problem
Conventional electrophotographic image forming apparatuses face issues such as image defects, developer contamination, and accelerated deterioration of the developing roller due to prolonged contact between the developing roller and photosensitive drum, which existing solutions have not adequately addressed.
Innovation Solution
A cartridge design featuring a movable developing member that can transition between a developing position and a separated position, utilizing a holding portion and movable member with contact and separating force receiving portions, and an urging portion to control the relative position and separation of the developing member from the photosensitive drum, minimizing unnecessary contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the developing roller is kept in contact with the photosensitive drum during non-development periods, then the developing roller can maintain its position, but image defects occur and the developing roller deteriorates faster
Solution Approach 1:
The developing roller is designed to be movable between a contact position (during development) and a separation position (during non-development). The holding portion can switch between holding the developing roller at the contact position and the separation position, allowing dynamic adjustment of the relative position between the developing roller and photosensitive drum based on operational requirements.
Solution Approach 2:
The harmful contact between the developing roller and photosensitive drum during non-development periods is eliminated by extracting the developing roller from the contact state. The holding portion releases the developing roller from the contact position, allowing it to be separated from the photosensitive drum, thereby removing the source of image defects and accelerated deterioration.
2Reliability
If the developing roller is separated from the photosensitive drum during non-development periods, then image defects are prevented, but the developing roller position becomes unstable
Solution Approach 1:
The system dynamically adjusts the holding portion's position between the contact position and separation position based on operational state. During development, the holding portion moves to the contact position to stabilize the developing roller; during non-development, it moves to the separation position to prevent contact while maintaining controlled positioning through the movable member mechanism.
Solution Approach 2:
The movable member acts as an intermediary between the holding portion and the developing roller. It receives contact force from the holding portion and transmits it to the developing roller, or allows separation controlled by the urging portion, thereby mediating the position control and enabling stable positioning both at contact and separation states.
3Manufacturing precision
If a movable member with multiple receiving portions is used, then precise control of contact and separation is achieved, but the device complexity increases
Solution Approach 1:
The movable member is designed with multiple receiving portions (contact force receiving portion and separating force receiving portion) that serve different functions within a single component. This multi-functional design allows one movable member to handle both contact and separation control, reducing the need for additional separate mechanisms and thereby limiting the increase in overall device complexity.
Solution Approach 2:
The contact force receiving portion and separating force receiving portion are combined into a single movable member structure. This merging of functions into one component simplifies the overall structure compared to using separate mechanisms for contact and separation control, while still achieving precise position control through the integrated design.
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 design reduces image defects, prevents developer contamination, and slows down the deterioration of the developing roller by optimizing the contact time with the photosensitive drum, enhancing the overall performance and longevity of the image forming apparatus.
Implementation Method 1
the elastic layer of the developing roller is may be deformed by the contact with the surface of the photosensitive drum
Implementation Method 2
a contact force receiving portion capable of receiving a contact force for moving the holding portion from the first position toward the second position
Implementation Method 3
a separating force receiving portion capable of receiving a separating force for moving the holding portion from the second position toward the first position
Implementation Method 4
an urging portion for urging the movable member placed at the first retracted position in a direction of moving the movable member toward the contact force receiving position
Data Source
AI summary
A cartridge includes a first unit including a photosensitive member and a first frame; a second unit including a developing member and a second frame; a holding portion movable between a first position for holding the second unit at the separated position and a second position for holding the second unit at the developing position; a movable member; and an urging portion. the movable member is movable to a contact force receiving position, a separating force receiving position separating force receiving portion, a first retracted position, and a second retracted position. The urging portion urges the movable member placed at the first retracted position in a direction of moving the movable member toward the contact force receiving position, and urges the movable member placed at the second retracted position in a direction of moving the movable member toward the separating force receiving position.