Conductive Photoreceptor Substrate Inner Roughness for Stable Rotation

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Solution Overview

Problem

Conductive substrates for electrophotographic photoreceptors experience significant wobbling during rotation, leading to image quality degradation due to uneven surface roughness at the end portions, which is not adequately addressed by existing technologies.

Innovation Solution

The conductive substrate is designed with a specific surface roughness profile, characterized by a sum S of intensity within a defined range (0.02 to 0.10) in the power spectrum of the inner circumferential surface at both end portions, reducing wobbling and enhancing rotational stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the inner circumferential surface of the conductive substrate is made smooth, then the rotational stability improves, but the manufacturing precision of surface roughness becomes more difficult to control within the specific range

Engineering Contradiction:
Improverotational stabilityVSAvoidsurface roughness control
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent specifies precise parameter ranges for surface roughness (sum S of intensity in power spectrum between 0.02-0.10) to optimize rotational stability. By defining quantitative parameters and their acceptable ranges, the invention transforms a qualitative requirement (smooth surface) into a controllable manufacturing specification, resolving the contradiction between achieving stability and maintaining manufacturing feasibility.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If water jetting processing is applied to the inner circumferential surface, then the surface roughness is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvesurface roughnessVSAvoidprocessing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent employs water jetting (hydraulic processing) to achieve the required surface roughness on the inner circumferential surface. This method uses high-pressure water streams to selectively remove material and create the desired roughness profile, providing a controllable and effective means to meet the surface quality requirements while managing processing complexity through established hydraulic technology.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 optimized surface roughness significantly reduces wobbling during rotation, thereby improving image quality by minimizing unevenness in image density and enhancing the performance of image forming apparatuses.

Implementation Method 1

subjecting an inner circumferential surface of a conductive substrate at both end portions in an axial direction to processing treatment by water jetting

Methodology Applied
Scientific EffectWater jetting: Jet Erosion

Data Source

PatentEP4610731A1Conductive substrate for electrophotographic photoreceptor, electrophotographic photoreceptor, process cartridge, image forming apparatus, and method for manufacturing conductive substrate for electrophotographic photoreceptor
Publication Date: 2025.09.03 FUJIFILM BUSINESS INNOVATION CORP
  • EP4610731A1 patent drawingFigure 1~2
  • EP4610731A1 patent drawingFigure 3
  • EP4610731A1 patent drawingFigure 4

AI summary

A conductive substrate for an electrophotographic photoreceptor includes a cylindrical conductive substrate, in which in a power spectrum obtained through fast Fourier transform of the roughness profile in the axial direction of the inner circumferential surface of the conductive substrate at both end portions in the axial direction, the sum S of intensity within the period range of 0.01 mm to 0.1 mm is 0.02 or greater and 0.10 or less.