Charging Member with Insulating Domains for Discharge Control
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Solution Overview
Problem
The increased speed of electrophotographic image forming processes leads to unstable charging of photosensitive members, resulting in strong local discharge and image unevenness, particularly at low temperatures and low humidity, when using conventional charging members.
Innovation Solution
A charging member with an electroconductive support, an electroconductive elastic layer containing exposed electrically insulating domains, and a surface layer of polymetalloxane, which reduces discharge start voltage and prevents abnormal discharge by enhancing electron release properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the charging speed is increased to improve productivity, then the image forming speed is improved, but strong local discharge occurs particularly at low temperature and low humidity
Solution Approach 1:
The patent applies local quality by creating electrically insulating domains within the electroconductive elastic layer. These domains are formed by adding an insulating substance to specific regions of the electroconductive layer, creating localized areas with different electrical properties. This allows the charging member to have high overall conductivity while preventing local discharge through the insulating domains, thus resolving the contradiction between fast charging and charging stability.
Solution Approach 2:
The patent uses composite materials by combining electroconductive elastic material with insulating substances to create the electroconductive elastic layer. This composite structure allows the layer to exhibit both electroconductivity (for fast charging) and localized insulation (for discharge prevention). The insulating domains are embedded within the electroconductive matrix, creating a composite material that simultaneously achieves high productivity and reliable charging.
2Productivity
If the charging time is reduced to improve productivity, then the image forming speed is improved, but stable charging of the photosensitive member cannot be ensured
Solution Approach 1:
The patent applies local quality by creating electrically insulating domains within the electroconductive elastic layer. These domains are formed by adding an insulating substance to specific regions of the electroconductive layer, creating localized areas with different electrical properties. This allows the charging member to have high overall conductivity while preventing local discharge through the insulating domains, thus resolving the contradiction between fast charging and charging stability.
Solution Approach 2:
The patent applies preliminary action by pre-forming the electroconductive elastic layer with embedded insulating domains before the charging process. This pre-structured layer is designed to control electron release and prevent abnormal discharge from the outset, enabling stable charging even at reduced charging times. The insulating domains are already in place to guide and regulate the discharge process before contact with the photosensitive member occurs.
3Stability of the object's composition
If an inorganic oxide coating film is formed to reduce electric resistance variation, then the electric resistance stability is improved, but strong local discharge still occurs at low temperature and low humidity
Solution Approach 1:
The patent applies local quality by creating electrically insulating domains within the electroconductive elastic layer. These domains are formed by adding an insulating substance to specific regions of the electroconductive layer, creating localized areas with different electrical properties. This allows the charging member to have high overall conductivity while preventing local discharge through the insulating domains, thus resolving the contradiction between fast charging and charging stability.
Solution Approach 2:
The patent uses composite materials by combining electroconductive elastic material with insulating substances to create the electroconductive elastic layer. This composite structure allows the layer to exhibit both electroconductivity (for fast charging) and localized insulation (for discharge prevention). The insulating domains are embedded within the electroconductive matrix, creating a composite material that simultaneously achieves high productivity and reliable charging.
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 charging member effectively prevents strong local discharge and ensures high-quality electrophotographic images by stabilizing the charging process even under low temperature and low humidity conditions.
Implementation Method 1
a surface layer containing a polymetalloxane having a structure represented by Structural Formula (a1)... prevents generation of strong local discharge (abnormal discharge) by enhancing electron release properties
Implementation Method 2
voltage is applied to a charging member disposed on the photosensitive member to be in contact therewith and very small discharge is generated near the contact portion between the charging member and the photosensitive member to charge the surface
Data Source
AI summary
A charging member is provided that has high charging ability and can prevent generation of abnormal discharge even under an environment at a low temperature and a low humidity. The charging member includes an electroconductive support, an electroconductive elastic layer and a surface layer. The electroconductive elastic layer contains electrically insulating domains such that at least a part of the electrically insulating domains is exposed on the surface of the electroconductive elastic layer. The surface layer contains a polymetalloxane having a structure represented by Structural Formula (a1), and M1 in Structural Formula (a1) and a carbon atom in a structural unit represented by Structural Formula (a2) are bonded through a linking group represented by Structural Formula (a3).