Drum Cartridge Coupling for Stable Torque Transmission
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Solution Overview
Problem
Existing electrophotographic image forming apparatuses face challenges in maintaining stable torque transmission to the photosensitive drum and developing roller, which affects the reliability and efficiency of the image forming process.
Innovation Solution
A cartridge design with a drum unit and drive transmission mechanism that includes a drum coupling and development coupling, allowing for stable torque transmission through a drum drive coupling and development drive coupling, ensuring synchronized rotation of the photosensitive drum and developing roller.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a coupling structure is used to transmit driving force from the main assembly to the cartridge, then the photosensitive drum can be rotated, but the torque transmission becomes unstable affecting image forming reliability
Solution Approach 1:
The patent applies dynamics by making the cartridge body rotatable relative to the main assembly while maintaining a fixed rotational center. The coupling structure transmits torque to rotate the entire cartridge body together with the photosensitive drum, ensuring stable torque transmission throughout the rotation process. This dynamic design resolves the contradiction by maintaining reliable torque transmission while enabling continuous rotation for image forming.
Solution Approach 2:
The cartridge body serves multiple functions: it holds the photosensitive drum, acts as the rotation axis support, and transmits torque from the coupling structure. By making the cartridge body itself the rotating element rather than just mounting the drum on a separate axis, the design achieves stable torque transmission while enabling the image forming process.
2Ease of operation
If the cartridge structure is simplified for easy mounting and dismounting, then user maintenance is improved, but the torque transmission mechanism becomes less reliable
Solution Approach 1:
The patent divides the system into separable modules: the cartridge body as a removable unit containing the photosensitive drum, and the main assembly with the coupling structure. This segmentation allows users to easily mount and dismount the entire cartridge as one piece while the internal coupling mechanism ensures reliable torque transmission during operation.
3Productivity
If the photosensitive drum rotation is accelerated to improve productivity, then image forming speed increases, but torque stability decreases affecting image quality consistency
Solution Approach 1:
The cartridge body is designed to rotate as a unified rigid structure around a fixed axis defined by the coupling mechanism. This dynamic design ensures that even at higher rotation speeds, the entire cartridge body including the photosensitive drum maintains stable rotation, preventing wobble or vibration that would compromise image quality consistency while enabling faster image forming.
Data Source
Figure 1(a)~1(b)
Figure 2
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AI summary
[TASK] To further develop prior art technique. [SOLUTION] A cartridge includes a photosensitive drum and a coupling, the coupling includes a main body and a movable member movable relative to the main body. The movable member includes an engaging portion which is capable of entering between a driving force application member and a braking force application member by the movement relative to the main body. The movable member receives a driving force for rotating the photosensitive drum, from the driving force application member and also receives a braking force applying a load against rotation of the photosensitive drum, from the braking force application member.