Electrophotographic Photosensitive Member Surface Structure for Streak Reduction
Solution Overview
Problem
Electrophotographic photosensitive members experience streak-like image defects in low printing modes under high-temperature and high-humidity environments, despite improvements in wear resistance and cleaning performance.
Innovation Solution
The introduction of convex and concave portions on the surface of electrophotographic photosensitive members, with specific width, depth, and slope configurations, to reduce friction and contact pressure, thereby stabilizing the cleaning blade and preventing image memory and streak formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a resin with high wear resistance is used in the surface layer to improve durability against electrical and mechanical external forces, then wear resistance is improved, but cleaning performance degrades
Solution Approach 1:
The invention introduces convex and concave portions with specific dimensional parameters (concave portion width: 30-100 μm, depth: 1-5 μm; convex portion slope distance: 300 μm or less) to create localized surface structures that improve cleaning performance in specific areas without compromising overall wear resistance. This local modification allows the high-wear-resistance resin to maintain its durability while the structured surface enhances cleaning blade contact and toner removal efficiency
2Reliability
If conventional surface structures are used to improve cleaning performance, then cleaning performance is improved, but streak-like image defects occur in low printing mode under high-temperature and high-humidity environments
Solution Approach 1:
The invention optimizes specific dimensional parameters of the surface structures to prevent streak defects. The concave portion width is controlled at 30-100 μm and depth at 1-5 μm, while the convex portion slope distance is limited to 300 μm or less. These parameter ranges create an optimal balance that ensures adequate cleaning performance while preventing the formation of streak-like image defects, particularly in challenging high-temperature and high-humidity printing conditions
3Reliability
If the surface is made smoother to reduce friction, then cleaning performance improves, but wear resistance decreases
Solution Approach 1:
The invention employs curved surface structures consisting of convex and concave portions with specific geometric parameters. The convex portions have controlled slope distances (300 μm or less) and the concave portions have specific widths (30-100 μm) and depths (1-5 μm). These curved structures optimize the contact between the cleaning blade and photosensitive member surface, reducing friction and improving cleaning performance while the underlying high-wear-resistance resin maintains durability
Data Source
AI summary
An electrophotographic photosensitive member, a process cartridge and an electrophotographic apparatus wherein a streak-like image defect otherwise occurring in output in a low printing mode performed under a H/H environment can be reduced are provided. A surface of the photosensitive member has a convex and concave portions continuously in a peripheral direction of the photosensitive member, and alternately in an axial direction of the photosensitive member, a width w of the concave portion is 30 to 100 μm, a depth d of the concave portion is 1 to 5 μm, the convex portion has a rising slope and a descending slope in the peripheral direction of the photosensitive member, and a distance from a starting point of the rising slope to an end point of the descending slope and a distance from a starting point of the descending slope to an end point of the rising slope are 300 μm or less.