UFP Collection in Image Forming Apparatus via Segmented Electrostatic Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current image forming apparatuses face challenges in efficiently collecting ultra-fine particles (UFP) less than 1 µm in size due to low electrostatic collection efficiency, and existing solutions either require costly upgrades or compromise on productivity.
Innovation Solution
An image forming apparatus with a UFP collecting means that includes a lattice-like plate with a high aperture ratio, a charging space with opposing electrodes, and a collecting space with a larger cross-section than the charging space, slowing air flow to enhance Brownian diffusion and electrostatic collection efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the electrostatic collecting technique is used to collect UFP, then the collection mechanism is simple, but the collecting efficiency for sub-micron particles is low
Solution Approach 1:
The collecting device is divided into two distinct spaces: a charging space for imparting electrostatic charge to UFP, and a collecting space with larger cross-section for enhanced Brownian diffusion and deposition. This segmentation allows each space to optimize its function, resolving the contradiction between simplicity and efficiency.
Solution Approach 2:
The cross-sectional area of the collecting space is increased relative to the charging space, and the air flow velocity is reduced in the collecting space. These parameter changes enhance Brownian diffusion and extend particle residence time, significantly improving collecting efficiency for sub-micron particles while maintaining a relatively simple device structure.
2Reliability
If the UFP agglomerating means (cyclone collecting means) is used to increase particle size, then the electrostatic collection efficiency is improved, but the device complexity and cost increase
Solution Approach 1:
The invention extracts and utilizes Brownian diffusion as a standalone collection mechanism in the collecting space, eliminating the need for cyclone agglomerating means. By creating a low-velocity region with larger cross-section, Brownian diffusion becomes the dominant collection mechanism, achieving efficient UFP collection without complex agglomerating devices.
3Reliability
If the temperature of the wall is increased to collect UFP by liquefaction, then the collection efficiency is improved, but the energy consumption increases
Solution Approach 1:
The invention replaces the thermal field-based collection method (liquefaction requiring high wall temperature) with a combined electrostatic field and Brownian diffusion mechanism. The charging space imparts electrostatic charge to particles, and the collecting space with larger cross-section and reduced flow velocity enables efficient Brownian diffusion and deposition, eliminating the need for high-temperature walls and associated energy consumption.
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 apparatus achieves significant improvement in UFP collection efficiency by prolonging the UFP's passage through the collecting space, allowing for effective deposition on electrodes, thereby enhancing productivity while maintaining a simple and cost-effective design.
Implementation Method 1
a charging means (200b) disposed in the charging space and imparts an electrostatic charge to the UFP
Implementation Method 2
slowing air flow to enhance Brownian diffusion and electrostatic collection efficiency
Data Source
Figure 1~2
Figure 3(a)~3(b)
Figure 4~5
AI summary
An image forming apparatus includes an image forming portion configured to form a toner image on a recording material; a fixing portion configured to fix the toner image on the recording material by heating the toner image formed on the recording material; a flow path including a first space connecting with the fixing portion and a second space connecting with the first space and through which air discharged from the fixing portion passes; a first electrode portion provided in the first space and provided with a first potential; and a second electrode portion provided in the second space and provided with a second potential different from the first potential. An air speed of the air passing through the second space is slower than an air speed of the air passing through the first space.