Photosensitive Drum Coupling With Integrated Brake and Visor
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Solution Overview
Problem
Existing electrophotographic image forming apparatuses face challenges in maintaining stable torque transmission and efficient mounting/dismounting of process cartridges, which can lead to operational inefficiencies and potential damage during cartridge handling.
Innovation Solution
The design incorporates a drum coupling mechanism that stabilizes the rotation of the photosensitive drum through a load generating member, and a drive transmission system that allows for seamless engagement and disengagement of the cartridge with the main assembly, using a tray system for collective mounting and dismounting of multiple cartridges without contact with the transfer belt, and a development separation control unit to manage contact operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a brake mechanism is added to the cartridge to prevent rotation during storage and transport, then reliability is improved, but device complexity increases
Solution Approach 1:
The brake mechanism is merged with the coupling structure itself. The coupling includes a brake component that integrates with the drive transmission elements, eliminating the need for a separate brake assembly. This allows the coupling to perform both drive transmission and braking functions through a unified structure, thereby improving reliability without proportionally increasing device complexity.
Solution Approach 2:
The brake mechanism is designed to engage automatically based on the rotational state of the photosensitive drum. When the drum rotates in the development direction, the brake component automatically disengages to allow motion. When rotation stops or reverses, the brake automatically engages to prevent unwanted rotation. This self-regulating mechanism eliminates the need for external control systems, maintaining simplicity while ensuring reliable rotation prevention.
2Adaptability or versatility
If the coupling structure is designed to accommodate both drive transmission and braking functions, then versatility is improved, but manufacturing precision requirements increase
Solution Approach 1:
The coupling is segmented into distinct functional zones: a drive transmission zone with teeth for motor engagement, a braking zone with friction surfaces, and a connection zone for the photosensitive drum. Each zone is optimized for its specific function with appropriate tolerances. The segmentation allows each component to be manufactured and assembled independently, reducing the cumulative precision requirements while achieving versatile multi-functionality.
Solution Approach 2:
Different regions of the coupling are designed with locally optimized properties. The drive transmission teeth are precision-machined for accurate motor coupling, while the brake surfaces are designed with slightly larger tolerances suitable for friction-based operation. The local quality approach allows each functional region to meet its specific precision requirements without requiring the entire coupling to be manufactured to the highest tolerance level, thereby reducing overall manufacturing complexity.
Data Source
Figure 1(a)~1(b)
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AI summary
The present invention relates to a cartridge comprising: a casing having a first end portion and a second end portion opposite from the first end portion; a photosensitive drum rotatably supported by the first end portion and the second end portion of the casing; and a coupling connected with the photosensitive drum so as to be capable of drive transmission, the coupling being provided adjacent to the first end portion of the casing, wherein the coupling includes a first shaped portion and a second shaped portion, the first shaped portion has a portion at a position which is more remote from the second end portion of the casing than the second shaped portion, a distance measured from the second end portion of the casing to the remote portion of the first shaped portion along an axis direction of the coupling decreases toward a downstream side in a rotational moving direction of the coupling, the second shaped portion has a first side portion at a position upstream and facing upstream in the rotational moving direction and a second side portion at a position downstream and facing downstream in the rotational moving direction, at least a part of the second shaped portion is more remote from an axis of the coupling than the remote portion of the first shaped portion in a radial direction of the coupling, the coupling is configured to transmit an external driving force receivable at the first side portion of the second shaped portion toward the photosensitive drum, the second side portion is configured to receive an external braking force, and the coupling includes a visor portion projecting outwardly in the radial direction of the coupling so as to cover a space downstream of the second shaped portion in the rotational moving direction.