Developing Roller Resin Layer for Toner Charge Control
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Solution Overview
Problem
In electrophotographic image forming processes, the non-magnetic single component development method faces issues with residual potential increase, toner scattering, and uneven charging due to the insulating silane coupling agent layer on the developing roller, leading to image quality problems.
Innovation Solution
A developing roller with an elastic silicone rubber layer and a resin layer composed of a polyurethane resin-silica hybrid as the principal component, which improves adhesion and charge leakage, preventing residual potential increase and toner scattering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a silane coupling agent layer is formed on the elastic layer to improve adhesion, then adhesion between layers is improved, but residual potential increases causing toner scattering and uneven charging
Solution Approach 1:
The patent removes the silane coupling agent layer from the structure. Instead of having elastic layer → silane coupling agent layer → fluorine-containing rubber layer, it directly forms the fluorine-containing rubber layer on the elastic layer, eliminating the insulating intermediate layer that causes residual potential accumulation
Solution Approach 2:
The patent uses a composite structure of elastic layer and fluorine-containing rubber layer with direct bonding. The fluorine-containing rubber layer itself provides both adhesion to the elastic layer and the necessary electrification properties, eliminating the need for a separate silane coupling agent layer
2Reliability
If multiple structural layers are provided on the elastic rubber layer to protect from scratches and produce sufficient toner electrification, then protection and electrification are improved, but residual potential increases leading to toner scattering
Solution Approach 1:
The patent eliminates the intermediate silane coupling agent layer that acts as an insulating barrier, allowing charge to leak properly while maintaining the protective and electrification functions through the direct contact between elastic layer and fluorine-containing rubber layer
Solution Approach 2:
The patent changes the electrical conductivity parameter by removing the insulating silane coupling agent layer, enabling proper charge leakage while maintaining mechanical protection and electrification through the optimized two-layer structure
3Reliability
If friction is applied to charge the toner layer on the developing roller, then toner electrification is achieved, but the elastic layer becomes locally deformed or distorted
Solution Approach 1:
The patent optimizes the material properties and layer structure to reduce the friction force needed for electrification. The fluorine-containing rubber layer provides efficient electrification with reduced friction, preventing elastic layer deformation while achieving necessary toner 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 solution inhibits residual potential increase, prevents toner scattering, and ensures uniform toner charging, resulting in improved image quality and extended printer operation without density unevenness or fog.
Implementation Method 1
a resin layer further provided on the elastic layer, wherein the resin layer contains a polyurethane resin-silica hybrid as a principal component
Implementation Method 2
friction is caused with this, in order to charge the toner
Implementation Method 3
charged via friction with a developer regulating member or such to conduct a development treatment
Implementation Method 4
a plurality of structural layers are provided on the elastic rubber layer in order to protect the outer layer surface from scratches, or to sufficiently produce toner electrification with a desired polarity
Data Source
AI summary
An objective is to provide a developing roller in which increase of residual potential is inhibited during repetitive operation without deteriorating adhesion to an elastic layer, scattering and leakage of toner are prevented, appropriate elasticity is exhibited and a resin layer capable of preventing uneven charging of toner and image unevenness is prepared, and also to provide a image forming method employing the developing roller. Disclosed is a developing roller possessing an elastic layer made of silicone rubber provided around a conductive shaft, and a resin layer further provided on the elastic layer, wherein the resin layer contains polyurethane resin-silica hybrid as a principal component.