Toner Fluidity and Chargeability in Image Forming Apparatus
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Solution Overview
Problem
Current image forming technologies face challenges in producing high-quality images in low-temperature and low-humidity environments due to issues with toner fluidity, chargeability, and contamination, leading to foggy images and reduced developer lifespan.
Innovation Solution
An image forming apparatus with a magnetic field generator, developing sleeve, and electric field generator that agitates a two-component developer to maintain optimal toner and carrier interaction, using a specific carrier and toner formulation with controlled particle sizes and additives to enhance fluidity and chargeability, and a coating process to prevent contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If inorganic particulate material is externally added to toner to improve fluidity, then transportability and mixability are improved, but the inorganic particulate material is soon buried in the toner by stress, resulting in deterioration of fluidity, feedability, developability and chargeability
Solution Approach 1:
The inorganic particulate material is surface-treated with a silane coupling agent before being added to the toner. This preliminary surface treatment creates a protective layer that prevents the inorganic particles from being buried by stress during storage and operation, thereby maintaining both fluidity and chargeability over time
Solution Approach 2:
The invention uses a composite structure where inorganic particulate material is combined with organic binder resin and surface-treated. This composite approach allows the inorganic particles to provide fluidity enhancement while the organic components and surface treatment protect against burial and degradation, maintaining long-term reliability
2Ease of operation
If inorganic particulate material is externally added to toner to improve fluidity, then transportability is improved, but the inorganic particulate material not fully mixed is released and floats to contaminate the apparatus and adhere to image bearer, resulting in filming of the toner
Solution Approach 1:
The inorganic particulate material undergoes surface treatment with silane coupling agent before being incorporated into the toner formulation. This preliminary preparation ensures that the inorganic particles are properly coated and integrated, preventing them from being released and floating during operation, thus eliminating contamination of the apparatus and image bearers
Solution Approach 2:
The silane coupling agent acts as an intermediary between the inorganic particulate material and the toner matrix. It creates a stable interface that prevents the inorganic particles from detaching and floating, thereby eliminating the harmful contamination effect while maintaining the fluidity benefits
3Ease of operation
If spherical toner is used to improve developability and transferability, then sphericity is improved, but the spherical toner easily rolls on image bearer and passes through cleaning blade, resulting in poor cleaning
Solution Approach 1:
The invention applies local quality modification by creating a controlled surface roughness on the spherical toner particles through the silane coupling treatment. This localized surface modification prevents the toner from rolling smoothly on the image bearer and passing through the cleaning blade, thereby improving cleaning quality while maintaining the spherical shape benefits for transferability
4Reliability
If developer increases average charge quantity in low-temperature and low-humidity environment, then chargeability is improved, but fluidity of the developer deteriorates, resulting in foggy images
Solution Approach 1:
The invention changes the physical and chemical parameters of the developer system by incorporating silane-treated inorganic particulate material and adjusting the binder resin composition. This parameter modification allows the developer to maintain fluidity even when average charge quantity increases in low-temperature and low-humidity environments, preventing foggy images while ensuring reliable chargeability
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 ensures reliable production of high-quality images with reduced fogging and extended developer lifespan by maintaining optimal toner and carrier interaction, fluidity, and preventing contamination, even in challenging environmental conditions.
Implementation Method 1
a magnetic field generator configured to generate a magnetic field
Implementation Method 2
a developing electric field generator configured to generate a developing electric field between the image bearer and the developer bearer
Implementation Method 3
an image developer configured to agitate the magnetic carrier and the toner to form two-component developer and develop the electrostatic latent image therewith
Implementation Method 4
transferring the toner image onto a transfer medium such as a transfer paper in a transfer process
Implementation Method 5
fixing the toner image thereon in a fixing process
Data Source
AI summary
An image forming apparatus including an image bearer, a magnetic field generator, a two-component developer bearer, a developing electric field generator, and an image developer. The two-component developer has at least a current speed index (25FRI) of from 0 to 2.0, which is determined by the following formula: 25FRI=(total energy at 10 mm/s/total energy at 100 mm/s). The total energy is an integral sum of a rotary torque and a vertical load when a blade of a powder fluidity analyzer spirally rotates at 10 mm/s and 100 mm/s, respectively, in the developer having a volume of 25 ml after idly agitated in the image developer for 10 minutes.