Tapered Restricting Protrusion for Even Static Elimination
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Solution Overview
Problem
In electrophotographic image forming apparatuses, the increased linear speed of the photosensitive drum reduces the time for static elimination, leading to trapped charge and ghost images due to exposure memory, and the static eliminating device's light emission is often shielded by a restricting protrusion, causing uneven light distribution.
Innovation Solution
A static eliminating device with a housing, substrate, light-emitting part, partition member, and restricting protrusion, where the restricting protrusion is tapered to support the partition member and maintain an opening for light emission, preventing toner adhesion and ensuring even light distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the linear speed of the photosensitive drum is increased to improve image forming speed, then productivity is improved, but the time for static elimination is reduced causing trapped charge and ghost images
Solution Approach 1:
The static eliminating device is disposed upstream of the cleaning device in the rotational direction of the photosensitive drum, performing static elimination before the drum surface reaches the cleaning section. This preliminary action ensures sufficient time for charge vanishing even at high linear speeds, preventing ghost image formation while maintaining high productivity
2Reliability
If the static eliminating device is disposed upstream of the cleaning device to secure sufficient static elimination time, then ghost image production is reduced, but the opening for light passage cannot secure sufficient vertical space
Solution Approach 1:
The substrate on which the light-emitting part is mounted is disposed in parallel with the outside surface of the housing, extending in the axial direction of the photosensitive drum rather than vertically. This dimensional change allows the opening to provide sufficient light passage area in the axial direction while maintaining the necessary vertical positioning for ghost image prevention
3Manufacturing precision
If a restricting protrusion is provided to support the partition member and maintain the opening position, then the opening position is restricted, but static eliminating light is shielded causing uneven intensity distribution
Solution Approach 1:
The restricting protrusion is designed with a tapered shape where the cross-sectional area decreases toward the distal end. This creates local quality variation along the protrusion, allowing the proximal portion to provide structural support and position restriction while the distal tapered portion minimizes light shielding, ensuring even static eliminating light distribution across the drum surface
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
The device effectively eliminates static charge on the photosensitive drum, reduces ghost image formation, and maintains even light intensity along the drum's surface, preventing light shielding and adhesion issues.
Implementation Method 1
a light-emitting part mounted on a mounting surface of the substrate and configured to emit static eliminating light
Data Source
AI summary
A static eliminating device includes: a housing; a substrate mounted to the housing; a light-emitting part mounted on a mounting surface of the substrate; a partition member connected to the housing to cover the substrate and the light-emitting part and face a portion of the housing to which the substrate and the light-emitting part are mounted so that an opening facing the surface of the image carrier is formed in a light-emitting region across which light is delivered from the light-emitting part to the surface of the image carrier; and a restricting protrusion abutting at a distal end thereof against the partition member to support the partition member and restricting the position of the partition member to ensure the formation of the opening. A distal side portion of the restricting protrusion located within the light-emitting region has a tapered shape narrowing with approach toward the partition member.