Process Cartridge Charging Member Matrix-Domain Structure
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Solution Overview
Problem
Existing electrophotographic processes face challenges in suppressing transfer black spots due to transfer currents, with existing solutions like rectifying layers, surface shape control, and matrix-domain structures being insufficient in effectively eliminating local unevenness and transfer memory.
Innovation Solution
A process cartridge with an electrophotographic photosensitive member and a charging member, where the photosensitive member has a potential distribution with a maximum average local potential difference of 2 V or more, and the charging member features a matrix-domain structure with a volume resistivity ratio of at least 1.00×105 times, ensuring electrical randomness in discharge distribution to effectively suppress transfer black spots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a corona type charging member is used, then charging capability is improved, but device size and power supply cost increase
Solution Approach 1:
The patent changes the electrical parameters of the charging member by using a roller type structure with controlled volume resistivity (10^8 to 10^14 Ω·cm) instead of corona discharge, achieving adequate charging capability with reduced device size and power requirements
Solution Approach 2:
The patent replaces the corona discharge mechanism with a direct contact roller charging mechanism, substituting a complex high-voltage electrical system with a simpler mechanical contact system that has lower power consumption and smaller size
2Reliability
If a corona type charging member is used, then charging capability is improved, but harmful factors increase
Solution Approach 1:
The patent replaces the corona discharge mechanism that generates ozone with a roller type charging member that makes direct contact with the photosensitive member, eliminating ozone generation while maintaining charging capability
Solution Approach 2:
The patent converts the harmful corona discharge process into a beneficial direct contact charging process, where the roller type charging member with specific resistivity characteristics provides uniform charging without generating harmful ozone
3Device complexity
If a DC charging type is used, then device size and power supply cost are reduced, but charging uniformity deteriorates
Solution Approach 1:
The patent optimizes the volume resistivity parameter of the charging member to a specific range (10^8 to 10^14 Ω·cm) that enables uniform charge distribution across the photosensitive member surface while using a compact DC power supply
Solution Approach 2:
The patent creates local quality variations in the charging member by controlling the volume resistivity distribution, allowing different regions to contribute appropriately to achieving uniform charging across the entire photosensitive member surface
4Reliability
If existing solutions like rectifying layers or matrix-domain structures are used, then transfer memory is suppressed, but transfer black spots are not effectively eliminated
Solution Approach 1:
The patent changes the potential distribution parameters on the photosensitive member surface by optimizing the charging member's volume resistivity, creating a potential distribution with maximum average local potential difference of 0.5 V or more that simultaneously suppresses transfer memory and eliminates transfer black spots
Solution Approach 2:
The patent uses a composite approach by combining a charging member with specific volume resistivity characteristics with a photosensitive member having controlled surface potential, creating a system that achieves both transfer memory suppression and transfer black spot elimination
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 combination of the photosensitive and charging members with specific structural and potential characteristics achieves efficient suppression of transfer black spots by eliminating spot-like potential distributions, improving image quality and reducing environmental ozone generation.
Implementation Method 1
the charging member has a matrix-domain structure including a polymer continuous phase and a polymer particulate phase... discharge in the transfer process can be controlled
Implementation Method 2
a polarity of a photosensitive member in charging is opposite to a polarity of the photosensitive member in transfer... chargeability varies depending on a transfer condition and a so-called transfer memory occurs
Data Source
AI summary
There is provided a process cartridge detachably attachable to a main body of an electrophotographic apparatus, the process cartridge including: an electrophotographic photosensitive member and a charging member, in which when average local potential differences of calculated lengths in the electrophotographic photosensitive member is calculated based on a specific method, a maximum value of the average local potential difference is 2 V or more, the charging member includes a support and an electro-conductive layer, the electro-conductive layer has a matrix and domains dispersed in the matrix, a volume resistivity ρM of the matrix is at least 1.00×105 times a volume resistivity ρD of the domain, and a specific calculated length SCP [μm] and a specific value relating a distance between the domains Dms [μm] satisfy SCP≥3×Dms.