Charge Roller Cleaning Timing via Dynamic Pixel Counting
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Solution Overview
Problem
Existing image forming apparatuses with a photosensitive drum cleaner-less configuration face issues with toner adherence to the charge roller, leading to image density unevenness and ghost images, particularly when the width of areas for pixel counting is limited, causing inaccurate timing for charge roller cleaning operations and decreased throughput.
Innovation Solution
An image forming apparatus that adjusts the width of areas for pixel counting based on the width of the recording material or image being printed, using a measuring unit to predict toner adherence and determine the optimal timing for charge roller cleaning, thereby reducing errors and maintaining throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the width of areas for pixel counting is reduced to improve measurement precision of toner adherence, then the accuracy of predicting toner accumulation improves, but the processing speed and memory capacity required increase, leading to increased device complexity and costs
Solution Approach 1:
The patent divides the photosensitive drum surface into multiple areas in the axial direction and counts pixels in each area separately. This segmentation allows accurate prediction of toner accumulation distribution while managing processing requirements by handling smaller discrete regions rather than the entire surface at once.
Solution Approach 2:
The patent dynamically adjusts the width of areas for pixel counting based on the width of the recording material or image being printed. This dynamic adaptation optimizes the balance between measurement precision and processing requirements for different printing scenarios, reducing unnecessary computational overhead.
2Measurement precision
If the width of areas for pixel counting is reduced to improve measurement precision, then the accuracy of predicting toner accumulation improves, but the processing speed decreases, leading to decreased productivity
Solution Approach 1:
The patent dynamically adjusts the width of areas for pixel counting based on the width of the recording material or image being printed. This dynamic adaptation optimizes the balance between measurement precision and processing speed for different printing scenarios.
Solution Approach 2:
The patent changes the parameter of area width for pixel counting based on printing conditions. By adjusting this parameter dynamically, the system maintains high measurement precision while adapting processing requirements to match the actual printing workload.
3Reliability
If a charge roller cleaning operation is performed frequently to prevent ghost images, then the image quality improves, but the throughput decreases due to interruptions in image formation
Solution Approach 1:
The patent uses pixel counting results from each area as feedback to determine when toner accumulation on the charge roller reaches a level that would cause ghost images. This feedback mechanism enables cleaning operations to be performed only when necessary, maintaining image quality while minimizing interruptions to throughput.
Solution Approach 2:
The patent performs pixel counting and predicts toner accumulation in advance during image formation, allowing the system to determine the optimal timing for cleaning operations before ghost images actually occur, rather than reacting after quality degradation is detected.
4Device complexity
If the width of areas for pixel counting is increased to reduce device complexity, then processing speed improves, but the accuracy of predicting toner accumulation decreases, leading to errors in cleaning timing
Solution Approach 1:
The patent segments the photosensitive drum surface into multiple areas and counts pixels in each segment. This segmentation strategy maintains measurement accuracy by keeping individual area widths small while managing overall processing requirements through divided computation.
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 accurately predicts toner adherence and optimizes the timing for charge roller cleaning, reducing the occurrence of ghost images and maintaining throughput even with limited area widths for pixel counting, thus addressing the challenge of suppressing decreases in throughput caused by cleaning operations.
Implementation Method 1
a charge unit configured to charge a surface of the photosensitive member to a predetermined potential
Implementation Method 2
an exposure unit including a light source configured to emit a light beam according to image data, the exposure unit configured to form a latent image on the photosensitive member by scanning the light beam
Implementation Method 3
a developing unit configured to develop the latent image formed by the exposure unit by toner to form a toner image
Implementation Method 4
a transfer unit configured to transfer the toner image onto the intermediate transfer member
Data Source
AI summary
The pixels counting unit divides an area in a main-scanning direction of a recording material on which image formation is performed into a plurality of areas 1 to n based on a width that is a length in the main-scanning direction of the recording material, and measures a pixels count with respect to each area among the plurality of areas 1 to n defined by dividing the area in the main-scanning direction of the recording material.