Elastic Blade Cleaning for Toner Adherence in Image Forming Apparatus
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Solution Overview
Problem
Existing electrophotographic image forming apparatuses face challenges in achieving high-quality images with improved resolution and gradation due to limitations in toner particle shape and size, leading to defective cleaning and adherence of external additives to the image bearer.
Innovation Solution
The use of an image forming apparatus with a toner containing mother particles and external additives, where the external additives have a number average particle diameter of 0.05 to 0.30 μm, and a cleaner with an elastic body blade having a surface elastic modulus of 15 to 25 N/mm² and a surface friction coefficient of 0.5 to 0.7, which forms a stable accumulation layer to prevent defective cleaning and adherence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If toner particles are made smaller with spherical shape through polymerization methods, then image resolution and gradation are improved, but external additives adhere to the image bearer causing defective cleaning
Solution Approach 1:
The patent changes the particle size parameter of external additives to a specific range (0.05 to 0.30 μm) to optimize both image quality and cleaning performance. This parameter adjustment prevents additive adherence while maintaining the benefits of small spherical toner particles for high-resolution imaging.
Solution Approach 2:
The patent uses a composite toner structure consisting of mother particles (0.5 to 2.0 μm) containing binder resin and colorant, with external additives (0.05 to 0.30 μm) coated on the surface. This composite structure allows the toner to maintain spherical shape and small effective particle diameter for high resolution while the controlled external additives prevent cleaning defects.
2Reliability
If conventional toner with larger particle diameter is used, then cleaning is easier, but image resolution and gradation deteriorate
Solution Approach 1:
The patent segments the toner particle into two distinct size components: mother particles (0.5 to 2.0 μm) providing structural integrity and ease of handling, and smaller external additives (0.05 to 0.30 μm) providing high-resolution imaging capability. This segmentation allows each component to fulfill its specific function optimally.
Solution Approach 2:
The patent applies different properties to different parts of the toner system: the mother particles have larger diameter for easy cleaning and handling, while the external additives have smaller diameter (0.05 to 0.30 μm) for high-resolution image formation. This local quality differentiation resolves the contradiction between cleaning ease and image resolution.
3Reliability
If cleaner blade pressure is increased to improve cleaning, then toner and additives adhere more to the image bearer, but if pressure is decreased, then cleaning becomes insufficient
Solution Approach 1:
The patent applies preliminary anti-action by controlling the external additive particle size (0.05 to 0.30 μm) and composition before the cleaning process occurs. This pre-configuration prevents toner and additive adherence to the image bearer, allowing the cleaner to operate effectively without causing harmful adherence effects.
Solution Approach 2:
The patent changes the physical parameters of external additives (particle size: 0.05 to 0.30 μm, composition ratio: 5 to 20 mass%) to create optimal cleaning conditions. These parameter changes enable effective cleaning at appropriate blade pressures without causing toner adherence, resolving the contradiction between cleaning effectiveness and preventing harmful factors.
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
This solution ensures high-quality image formation by preventing defective cleaning and adherence of external additives, maintaining stable contact under various environmental conditions and extending the period of high-quality image production.
Implementation Method 1
The contact part has a surface elastic modulus in the range of 15 to 25 N/mm2 and a surface friction coefficient in the range of 0.5 to 0.7
Implementation Method 2
The blade member slidably abrades the surface of the image bearer at a blade nip part formed therebetween while undergoing elastic deformation
Implementation Method 3
a charger to charge a surface of the image bearer
Implementation Method 4
an irradiator to irradiate the charged surface of the image bearer with light to form an electrostatic latent image thereon
Implementation Method 5
a developing device to develop the electrostatic latent image with a toner to form a toner image
Implementation Method 6
a transfer device to transfer the toner image onto a transfer medium
Data Source
AI summary
An image forming apparatus is provided which includes an image bearer, a charger, an irradiator, a developing device to develop an electrostatic latent image on the image bearer with a toner to form a toner image, a transfer device to transfer the toner image onto a transfer medium, and a cleaner to remove toner particles remaining on the image bearer without being transferred. The toner includes a mother particle including a binder resin and a colorant and one or more external additives. At least one of the external additives includes primary particles having a number average particle diameter in the range of 0.05 to 0.30 μm. The cleaner includes an elastic body blade having a contact part with the image bearer. The contact part has a surface elastic modulus in the range of 15 to 25 N/mm2 and a surface friction coefficient in the range of 0.5 to 0.7.