Photosensitive Drum Cleaning Roller Toner Layer Control
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Solution Overview
Problem
Conventional cleaning devices for photosensitive drums in image forming apparatuses face challenges in maintaining a proper quantity of toner on the cleaning roller, leading to ineffective surface polishing and potential contamination of the charging unit due to uneven toner distribution and point contact mechanisms.
Innovation Solution
A cleaning device with a cleaning roller, a cleaning blade, and a layer control member, where the layer control member includes an upstream scraper that contacts the cleaning roller in a trail direction and a downstream scraper that line contacts it in a counter direction, ensuring a controlled thickness of toner for continuous polishing and preventing toner contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single scraper line contacts the cleaning roller in counter direction, then the structure is simple, but most remaining toner is scraped away and proper quantity cannot be held
Solution Approach 1:
The single scraper is divided into two separate scrapers: an upstream scraper that surface contacts the cleaning roller in trail direction, and a downstream scraper that line contacts in counter direction. This segmentation allows each scraper to perform a specific function - the upstream scraper retains toner while the downstream scraper controls thickness, achieving proper toner quantity without excessive complexity.
Solution Approach 2:
Instead of using a single scraper contacting in counter direction, the invention introduces an upstream scraper contacting in trail direction (opposite direction). This inversion of contact direction allows the upstream scraper to gently retain toner on the cleaning roller surface without scraping it away, while the downstream scraper maintains its thickness control function.
2Device complexity
If the scraper only line contacts the cleaning roller in counter direction, then the contact mechanism is simple, but point contact in sectional view causes uneven toner distribution
Solution Approach 1:
The contact mechanism is segmented into two types: surface contact by the upstream scraper and line contact by the downstream scraper. This segmentation allows the upstream scraper to distribute toner evenly across the surface while the downstream scraper provides precise thickness control through line contact, achieving uniform toner layer without excessive complexity.
Solution Approach 2:
Different contact modes are applied at different locations: the upstream scraper uses surface contact to ensure even distribution across the cleaning roller surface, while the downstream scraper uses line contact for precise thickness control at a specific location. This local differentiation of contact quality achieves uniform toner layer.
3Object-generated harmful factors
If most remaining toner is scraped away, then the cleaning roller is clean, but continuous polishing cannot be maintained and external additive contaminates charging unit
Solution Approach 1:
The upstream scraper contacts the cleaning roller in trail direction (opposite to conventional counter direction contact), which allows it to retain rather than scrape away toner. This inversion ensures that a proper quantity of toner with external additive remains on the cleaning roller for continuous polishing, preventing contamination of the charging unit while maintaining reliability.
Solution Approach 2:
The upstream scraper acts as an intermediary that gently retains toner on the cleaning roller surface without completely removing it. This intermediary function ensures that sufficient toner with external additive remains to continuously polish the photosensitive drum surface, preventing both contamination and loss of polishing capability.
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 solution allows for effective toner adhesion and distribution on the cleaning roller, maintaining low friction on the photosensitive drum surface and preventing external additives from adhering to the drum, thus ensuring continuous and reliable image formation.
Implementation Method 1
a cleaning roller and a cleaning blade may be used to contact the surface of the photosensitive drum... The cleaning roller uses the toner containing the external additive to remove substances, such as corona discharge products adhering to the surface of the photosensitive drum
Implementation Method 2
The toner contains a very small quantity of an external additive... The toner adheres to the electrostatic latent image to form a toner image
Implementation Method 3
a cleaning blade may be used to contact the surface of the photosensitive drum... remove remaining toner from the surface of the photosensitive drum
Data Source
AI summary
A cleaning device for a photosensitive drum includes a cleaning roller, a cleaning blade, and a layer control member. The layer control member may include an upstream scraper having a surface that surface contacts the cleaning roller in a substantially same direction as a rotation direction of the cleaning roller. In addition, the layer control member may include a downstream scraper having an edge that contacts the cleaning roller. The downstream scraper may be positioned downstream of the contact position between the cleaning roller and the upstream scraper in the rotation direction of the cleaning roller. In some embodiments, the downstream scraper edge may line contact the cleaning roller in a direction opposing the rotation direction of the cleaning roller.