Toner Circularity and Friction for Photoreceptor Cleaning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In image forming apparatuses using electrophotographic methods, the overcoat layer on the photoreceptor makes it difficult to remove corona products under high temperature and high humidity conditions, leading to image flow issues due to the harder overcoat layer not being easily scraped by the cleaning blade.
Innovation Solution
The use of a specific toner with a binder resin containing crystalline polyester, a colorant, and a release agent, with toner particles having a specific average circularity and size distribution, enhances the cleaning efficiency by increasing the dynamic frictional force between the photoreceptor and the cleaning blade, effectively removing corona products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an overcoat layer is provided on the photoreceptor to protect the photosensitive layer, then the photoreceptor's durability and charge retention are improved, but the cleaning blade cannot effectively remove corona products under high temperature and high humidity conditions
Solution Approach 1:
The invention changes the physical and chemical parameters of the toner particles, specifically controlling the circularity to 0.970 or more and using a binder resin with a glass transition temperature of -50°C or lower. These parameter changes enable the toner to effectively remove corona products even under high temperature and high humidity conditions while maintaining the overcoat layer's protective function.
Solution Approach 2:
The invention uses a composite toner structure consisting of a binder resin and a colorant, where the binder resin has specific properties (glass transition temperature of -50°C or lower). This composite material approach allows the toner to have both the necessary adhesion to the photoreceptor and the ability to effectively remove corona products through dynamic frictional force.
2Strength
If the overcoat layer is made harder to improve scratch resistance, then the photoreceptor's wear resistance is improved, but the cleaning blade cannot scrape off corona products effectively
Solution Approach 1:
The invention changes the parameters of the toner particles, specifically controlling circularity to 0.970 or more and using a binder resin with a glass transition temperature of -50°C or lower. These changes enable the toner to generate sufficient dynamic frictional force to remove corona products from the hard overcoat layer surface without compromising the layer's scratch resistance.
3Device complexity
If regular toner is used, then the image formation process is simple, but image flow occurs under high temperature and high humidity conditions
Solution Approach 1:
The invention changes the glass transition temperature parameter of the binder resin to -50°C or lower, which prevents image flow under high temperature and high humidity conditions. The toner maintains good image quality and stability while the image formation process remains relatively simple.
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 specific toner configuration prevents image flow under high temperature and high humidity conditions by improving the cleaning efficiency, ensuring stable image formation and reducing streaky defects.
Implementation Method 1
a tip of the cleaning blade contacts with the electrophotographic photoreceptor toward the direction opposite to a rotation direction of the electrophotographic photoreceptor to remove a residue on the surface
Implementation Method 2
a charge unit that charges a surface of the electrophotographic photoreceptor
Implementation Method 3
an electrostatic latent image forming unit that forms an electrostatic latent image on the charged surface of the electrophotographic photoreceptor
Implementation Method 4
a developing unit that contains a developer containing toner particles, and develops the electrostatic latent image formed on the surface of the electrophotographic photoreceptor with the developer to form a toner image
Implementation Method 5
a transfer unit that transfers the toner image to a surface of a recording medium
Implementation Method 6
a fixing unit that fixes the toner image transferred on the recording medium
Data Source
AI summary
An image forming apparatus includes an electrophotographic photoreceptor having an overcoat layer and a cleaning unit that includes a cleaning blade and a tip of the cleaning blade contacts with the photoreceptor toward the direction opposite to the rotation direction, wherein the toner particle contains a crystalline polyester resin, an average circularity of the toner particles is from 0.955 to 0.971, a content ratio of the toner particles having a particle diameter of 4.5 μm or more and less than 7.5 μm and a circularity of 0.980 or more is from 16% by number to 40% by number, and a content ratio of the toner particles having a particle diameter of 7.5 μm or more and less than 15 μm and a circularity of 0.900 or more and less than 0.940 is 3% by number or less.