Electroconductive Member Structure for White Spot Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In high-speed and long-lifetime electrophotographic image forming processes, especially in cleaner-less configurations, electroconductive members face challenges in preventing the occurrence of white spot images due to dirt substances adhering to the charging member, leading to abnormal discharge and image quality issues.
Innovation Solution
An electroconductive member with a specific matrix-domain structure, comprising a crosslinked product of first and second rubbers and electroconductive particles, where the first particles are present as primary particles in the matrix and the second particles are dispersed in domains with a small average diameter, ensuring effective charge distribution and suppression of excessive discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If electroconductive members are used in high-speed and long-lifetime electrophotographic image forming processes, then productivity and duration of action are improved, but dirt substances adhere to the charging member causing white spot images and image quality deteriorates
Solution Approach 1:
The patent applies local quality by creating a matrix-domain structure where domains with different electroconductive particle sizes are distributed throughout the electroconductive layer. The matrix contains first electroconductive particles (200 nm or more) while domains contain second electroconductive particles (50 nm or less), creating localized regions with different charge distribution characteristics that prevent dirt accumulation and white spot formation
Solution Approach 2:
The patent uses composite materials by combining two types of electroconductive particles (first particles ≥200 nm and second particles ≤50 nm) within a rubber matrix. This composite structure creates a heterogeneous electroconductive layer with optimized charge distribution properties that maintain image quality during high-speed operation
2Duration of action of stationary object
If electroconductive members operate for extended periods, then duration of action is improved, but charge accumulation occurs leading to abnormal discharge and reliability decreases
Solution Approach 1:
The matrix-domain structure creates localized regions (domains) with fine electroconductive particles that provide controlled charge distribution. This local heterogeneity prevents uniform charge accumulation across the entire surface, thereby preventing abnormal discharge and maintaining reliable operation over extended periods
Solution Approach 2:
The patent changes the parameter of electroconductive particle size distribution by incorporating two distinct size ranges (≥200 nm and ≤50 nm). This parameter change creates varying charge transport pathways that prevent charge accumulation and maintain stable discharge characteristics during long-term operation
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 electroconductive member effectively suppresses the occurrence of white spot images by preventing charge accumulation and ensuring stable, high-quality image formation over extended periods in high-speed electrophotographic processes.
Implementation Method 1
The electroconductive member has a function to transport charge from the electroconductive support to the surface of the electroconductive member and apply the charge to the abutment object by discharge or triboelectric charging
Implementation Method 2
The charging member is a member for generating discharge between the charging member and an electrophotographic photosensitive member to charge the surface of the electrophotographic photosensitive member
Implementation Method 3
The developing member is a member for controlling the charge of a developer covering the surface of the developing member by triboelectric charging to give uniform charge quantity distribution to the developer
Data Source
AI summary
An electroconductive member for electrophotography including a support having electro-conductivity and an electroconductive layer on the outer surface of the support, the electroconductive layer including a matrix containing a crosslinked product of a first rubber and first electroconductive particles and domains each containing a crosslinked product of a second rubber and second electroconductive particles, wherein at least part of the first electroconductive particles are present as a primary particle in the crosslinked product of the first rubber, wherein, the first electroconductive particles of the matrix observed in a specific observation region have d1 of 200 nm or more, the second electroconductive particles in the domains observed therein have d2 of 50 nm or less, and 80 number % or more of the domains satisfy specific conditions.