Photoconductor Charging Control via Dynamic AC Voltage Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image formation apparatuses face challenges in suppressing both uneven charging and corona product deposition on photoconductors, as lowering the AC voltage to prevent corona product deposition leads to uneven charging, and vice versa, degrading image quality.
Innovation Solution
An image formation apparatus with a charging section that applies a bias voltage with superposed AC and DC voltages, a controller to adjust AC voltage based on DC current fluctuations, and a detector to monitor DC current, ensuring the AC voltage remains within a range that prevents both uneven charging and corona product deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the AC voltage is lowered to prevent corona product deposition, then corona product deposition is suppressed, but uneven charging occurs and image quality is degraded
Solution Approach 1:
The patent applies dynamics by making the AC voltage adjustable rather than fixed. The charging device dynamically changes the AC voltage component based on detected photoconductor surface potential to maintain optimal charging conditions. This allows the system to adapt between preventing corona deposition and ensuring uniform charging depending on actual operating conditions.
Solution Approach 2:
The patent changes the voltage parameter by separating the bias voltage into DC and AC components, where the DC component provides the base charging voltage and the AC component modulates to prevent corona. By independently controlling these parameters, the system achieves both uniform charging and corona prevention.
2Manufacturing precision
If the AC voltage is increased to ensure uniform charging, then charging uniformity is improved, but corona product is deposited on the photoconductor surface
Solution Approach 1:
The system dynamically adjusts the AC voltage component based on real-time detection of photoconductor surface potential. When corona deposition is detected or predicted, the AC voltage is reduced. When uniform charging is insufficient, the AC voltage is increased, creating a dynamic balance between the two competing requirements.
Solution Approach 2:
The patent implements feedback control by detecting the photoconductor surface potential and using this information to adjust the AC voltage component of the bias voltage. This closed-loop control ensures that the charging conditions are continuously optimized to prevent both corona deposition and uneven charging.
3Duration of action of stationary object
If a high-hardness material is used for the photoconductor surface layer to suppress abrasion, then photoconductor life is prolonged, but corona product deposition increases
Solution Approach 1:
The patent introduces an intermediary control mechanism (AC voltage component with feedback control) that mediates between the photoconductor material properties and the charging process. The AC voltage acts as a mediator to prevent corona deposition on the high-hardness surface without compromising the abrasion resistance benefits.
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 effectively controls the AC voltage to balance between preventing uneven charging and corona product deposition, maintaining image quality by dynamically adjusting the AC voltage in response to DC current fluctuations, thus optimizing photoconductor surface potential.
Implementation Method 1
a charging section that applies a bias voltage having an AC voltage superposed on a DC voltage to the photoconductor so as to charge the photoconductor
Implementation Method 2
a detector that detects the DC current
Data Source
AI summary
An image formation apparatus is provided and includes: a photoconductor; a charging section that applies a bias voltage having an AC voltage superposed on a DC voltage to the photoconductor so as to charge the photoconductor; a controller that controls at least one of the AC voltage and an AC current in response to a fluctuation amount of a DC current flowing between the photoconductor and the charging section when an AC voltage is applied; and a detector that detects the DC current.