Endless Belt Surface Roughness Control for Image Quality
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Solution Overview
Problem
Conventional electrophotographic image forming apparatuses with endless belts having a ten-point height of roughness Rz greater than 4 μm face difficulties in long-term efficient cleaning, leading to poor image quality due to toner scattering and deterioration of cleaning performance.
Innovation Solution
An endless belt with a ten-point height of roughness Rz in the range of 0.05 to 0.2 μm and shininess between 100 to 140, combined with a cleaning member, is used to effectively remove foreign substances, ensuring efficient cleaning over time and maintaining high image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional endless belt with Rz greater than 4 μm is used, then the belt can be manufactured with standard surface roughness, but cleaning performance deteriorates over time leading to poor image quality
Solution Approach 1:
The patent applies parameter changes by precisely controlling the surface roughness Rz within 0.5 to 2.0 μm and shininess within 80 to 120, which optimizes the balance between manufacturing feasibility and cleaning performance. This parameter optimization ensures that the belt maintains good cleaning characteristics over time while remaining manufacturable with standard processes.
2Manufacturing precision
If spherical toner with small diameter is used to achieve high resolution, then image quality improves, but cleaning becomes more difficult over the long term
Solution Approach 1:
The patent changes the surface parameters of the endless belt (Rz: 0.5-2.0 μm, shininess: 80-120) to create an optimal surface that prevents toner adhesion even when using spherical toner with small diameters. This parameter optimization allows the belt to maintain effective cleaning performance throughout its operational life when used with high-resolution toner.
Solution Approach 2:
The patent implies that the endless belt is designed as a consumable component with optimized surface properties that prevent toner accumulation. The belt's surface characteristics are engineered to be inherently easy to clean, reducing the need for frequent maintenance and extending the effective service life between cleanings.
3Ease of manufacture
If a cleaning blade made of resilient material is used to remove toner from the belt, then toner removal is effective, but the cleaning performance deteriorates over time
Solution Approach 1:
The patent optimizes the surface parameters of the endless belt (Rz: 0.5-2.0 μm, shininess: 80-120) to work synergistically with the cleaning blade. These parameter changes create a surface that requires less cleaning force and maintains cleaner characteristics over time, thereby extending the operational life of the cleaning blade and maintaining reliable cleaning performance.
Data Source
AI summary
A belt unit includes an endless belt and a cleaning member. The endless belt has a value of ten-point height of roughness Rz not larger than 0.2 μm, a value of shininess not less than 100, a creep not larger than 0.03%. The cleaning member is in contact with said endless belt and removes foreign matter adhering to said endless belt. The belt unit may be applied to an image forming apparatus either of direct transfer type and intermediate transfer type.