Image Forming Apparatus Residual Charge Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image forming apparatuses face challenges in stabilizing static elimination performance on photoconductors with surface protection layers, particularly in removing residual charges effectively, which can lead to deteriorated image quality and reduced device lifespan.
Innovation Solution
The apparatus incorporates a switching mechanism between exposure static elimination and transfer static elimination sections, using direct current charging and electrostatic transfer methods to manage residual charges based on threshold levels and environmental conditions, ensuring efficient static elimination without exceeding allowable limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If exposure static elimination is used to eliminate residual charge on the photoconductor surface, then static elimination performance is improved, but the photoconductor life is reduced due to degradation from repeated exposure
Solution Approach 1:
The patent changes the method parameter for static elimination by switching between exposure-based elimination and transfer-based elimination depending on the residual charge level. When residual charge is high, transfer static elimination is used to avoid excessive exposure that would degrade the photoconductor. When residual charge is low, exposure static elimination is used for effective elimination. This dynamic parameter adjustment resolves the contradiction between elimination effectiveness and photoconductor longevity.
2Duration of action of stationary object
If transfer static elimination is used to eliminate residual charge, then photoconductor life is extended by reducing exposure, but static elimination performance may be insufficient for high residual charge levels
Solution Approach 1:
The system dynamically selects the static elimination method based on the measured residual charge level. This parameter-based switching ensures that transfer static elimination (less damaging but less effective) is used only when necessary, while exposure static elimination (more effective but more damaging) is used when the residual charge level warrants it. This resolves the contradiction by adapting the elimination method to the actual charge conditions.
Solution Approach 2:
The patent implements a feedback mechanism where the residual charge level is measured and used to determine the appropriate static elimination method. This closed-loop control ensures that the photoconductor is not unnecessarily exposed when residual charge is already low, extending its life, while still achieving effective static elimination when charge levels are high.
3Productivity
If direct current charging is used to charge the photoconductor surface, then charging efficiency is improved, but residual charge removal becomes more difficult compared to alternating current charging
Solution Approach 1:
The patent compensates for the difficulty of removing DC charging residues by implementing a switching mechanism between exposure and transfer static elimination methods. The system monitors residual charge levels and selects the appropriate elimination method, ensuring that DC charging's efficiency benefits are maintained while its residual charge removal disadvantage is overcome through method diversification.
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 approach stabilizes static elimination performance, improves image quality by reducing toner fog and carrier discharge, and extends the life of the image holding section by effectively managing residual charges across varying conditions.
Implementation Method 1
a charging section that charges a surface of the image holding section with a direct current potential
Implementation Method 2
an exposure section that exposes the surface of the image holding section charged by the charging section to form an electrostatic latent image
Implementation Method 3
a transfer section that electrostatically transfers a visible image formed on the image holding section to a transfer medium
Implementation Method 4
an exposure static elimination section that eliminates a residual charge of the image holding section by using the exposure section when image formation on the image holding section is stopped
Implementation Method 5
a transfer static elimination section that eliminates the residual charge of the image holding section by using at least the transfer section when the image formation on the image holding section is stopped
Data Source
AI summary
An image forming apparatus includes: an image holding section that includes a photoconductor having a surface protection layer; a charging section that charges a surface of the image holding section with a direct current potential; an exposure section that exposes the surface of the image holding section charged by the charging section to form an electrostatic latent image; a developing section that develops the electrostatic latent image formed on the image holding section; a transfer section that electrostatically transfers a visible image formed on the image holding section to a transfer medium; an exposure static elimination section that eliminates a residual charge of the image holding section by using the exposure section when image formation on the image holding section is stopped; a transfer static elimination section that eliminates the residual charge of the image holding section by using at least the transfer section when the image formation on the image holding section is stopped; and a switching section that causes the exposure static elimination section to perform static elimination under a condition that the residual charge of the image holding section does not exceed a threshold value of an allowable static elimination level at which the residual charge is eliminated by the exposure static elimination section, and causes the transfer static elimination section instead of the exposure static elimination section to perform static elimination under a condition that the residual charge exceeds the threshold value.