Proximity Charger Voltage Control for Photoreceptor Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image forming apparatuses face challenges in deriving a proper peak-to-peak voltage for charging, which is affected by ambient temperature and photoreceptor film thickness, leading to issues like toner fogging and excessive abrasion.
Innovation Solution
An image forming apparatus that includes a charger, a power source unit to apply varying charging voltages, an amperometric detector to measure alternating current, and a processor to derive characteristic lines for forward and reverse discharge ranges, adjusting the peak-to-peak voltage based on the difference in slope between these lines to ensure proper charging regardless of temperature and film thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a fixed peak-to-peak voltage is used for charging, then the charging process is simple, but the charged potential becomes non-uniform due to environmental conditions and film thickness variations
Solution Approach 1:
The patent applies dynamics by making the peak-to-peak voltage adjustable rather than fixed. The control unit dynamically changes the peak-to-peak voltage based on detected film thickness and environmental conditions, allowing the charging system to adapt to varying conditions while maintaining uniform charged potential on the photoreceptor drum surface.
Solution Approach 2:
The patent changes the voltage parameter (peak-to-peak voltage) based on detected conditions. The control unit modifies the peak-to-peak voltage within a predetermined range according to film thickness and environmental factors, ensuring uniform charging across different operating conditions without requiring complex structural changes.
2Manufacturing precision
If the peak-to-peak voltage is increased to charge thick films, then charging coverage improves, but toner fogging occurs due to excessive voltage
Solution Approach 1:
The patent changes the peak-to-peak voltage parameter based on detected film thickness. For thick films, the control unit increases the peak-to-peak voltage within safe limits to ensure adequate charging coverage. For thin films, the voltage is reduced to prevent toner fogging. This dynamic parameter adjustment allows the system to optimize charging coverage while avoiding harmful effects.
Solution Approach 2:
The patent uses feedback from the film thickness detector to control the peak-to-peak voltage. The detected film thickness information is fed back to the control unit, which then adjusts the peak-to-peak voltage accordingly. This closed-loop feedback mechanism ensures that the voltage is optimized for each specific film thickness, preventing both insufficient charging and toner fogging.
3Productivity
If a high peak-to-peak voltage is applied to ensure adequate charging, then charging efficiency improves, but photoreceptor drum abrasion increases
Solution Approach 1:
The patent dynamically adjusts the peak-to-peak voltage parameter based on detected film thickness and environmental conditions. The control unit applies higher peak-to-peak voltages only when necessary for thick films or specific conditions, while using lower voltages for thin films to minimize abrasion. This optimized parameter control maintains charging efficiency while protecting the photoreceptor drum from excessive wear.
Solution Approach 2:
The system uses feedback from film thickness detection to control the peak-to-peak voltage level. The detected information feeds back to the control unit, which adjusts the voltage to the minimum necessary level for adequate charging. This feedback mechanism prevents unnecessarily high voltages that would cause excessive abrasion, while still ensuring sufficient charging efficiency.
4Manufacturing precision
If the charging voltage is adjusted for each film thickness, then charging uniformity improves, but the control process becomes more complex
Solution Approach 1:
The patent changes the peak-to-peak voltage parameter based on film thickness categories. The control unit divides the operational range into discrete voltage levels corresponding to different film thickness ranges. This discrete parameter adjustment simplifies the control logic compared to continuous adjustment, while still achieving uniform charging across different film thicknesses.
Solution Approach 2:
The system dynamically selects from predetermined voltage levels based on detected film thickness. Rather than continuously adjusting voltage, the control unit transitions between discrete voltage levels corresponding to different film thickness categories. This dynamic discrete control reduces computational complexity while maintaining charging uniformity across varying conditions.
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 effectively derives and applies a suitable peak-to-peak voltage, preventing toner fogging and minimizing photoreceptor drum abrasion by accounting for environmental conditions and film thickness, ensuring consistent and high-quality image formation.
Implementation Method 1
A superimposed voltage of a DC voltage and an AC voltage is applied to the charger so that the charger can charge the surface of the photoreceptor drum uniformly
Implementation Method 2
an amperometric detector configured to detect values of alternating current flowing in the charger during application of the plurality of charging voltages
Data Source
AI summary
An image forming apparatus has: an image supporting member, a charger, a power source unit, an amperometric detector, and a processor. The power source unit applies a plurality of charging voltages, which includes alternating voltages respectively, to the charger sequentially while no print medium is fed. The alternating voltages have different peak-to-peak voltages for a forward discharge range and different peak-to-peak voltages for a reverse discharge range, respectively. The amperometric detector detects values of alternating current flowing in the charger during application of the charging voltages. The processor derives characteristic lines of alternating current value with respect to alternating voltage for the forward discharge range and for the reverse discharge range, respectively, from the values detected by the amperometric detector. The processor derives a peak-to-peak voltage to be used in a process in a different way depending on a difference in slope between the characteristic lines.