Developing Roller Toner Management for Low Dot Density
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Solution Overview
Problem
Conventional image forming apparatuses face issues with residual toner deterioration and poor print quality due to uneven dot population density, leading to spoiled images and inefficient toner consumption, especially when printing images with low dot population density.
Innovation Solution
An image forming apparatus equipped with a computing section and controller that divides the image data into sub-data areas and adjusts the toner supply based on calculated dot population density, transferring excess toner from the developing roller to the photoconductive drum for waste collection, thereby maintaining image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If an image with low dot population density is printed repeatedly, then toner consumption is reduced, but residual toner on the developing roller deteriorates
Solution Approach 1:
The printable area is divided into multiple sub-data areas along the traveling direction of the print medium. The computing section calculates dot population density for each sub-data area separately, enabling differentiated toner management strategies for different regions. This segmentation allows the system to identify specific areas with low dot population density and apply targeted residual toner removal only where needed.
Solution Approach 2:
The system applies different developing conditions and residual toner removal strategies to different sub-data areas based on their specific dot population density characteristics. Areas with low dot population density receive enhanced residual toner removal, while areas with normal or high dot population density use standard processing. This local differentiation prevents unnecessary toner removal in high-density areas while effectively addressing residual toner issues in low-density areas.
2Reliability
If residual toner is removed from the developing roller, then toner deterioration is prevented, but image quality may be affected
Solution Approach 1:
By dividing the printable area into sub-data areas and calculating dot population density for each segment, the system can precisely identify which regions require residual toner removal. This segmentation enables targeted intervention only in low dot population density areas, avoiding unnecessary toner removal from high-density areas that would compromise image quality.
Solution Approach 2:
The computing section continuously monitors dot population density calculations from sub-data areas and provides feedback to the controller. Based on this feedback, the controller dynamically adjusts developing conditions and residual toner removal operations. This closed-loop feedback mechanism ensures that toner removal is performed only when and where necessary, maintaining optimal image quality while preventing toner deterioration.
3Device complexity
If the entire printable area is treated uniformly, then processing is simplified, but residual toner cannot be collected thoroughly from areas with high dot population density
Solution Approach 1:
The printable area is segmented into multiple sub-data areas along the traveling direction, with each area being independently evaluated for dot population density. This segmentation enables the system to distinguish between areas with high and low dot population density, allowing thorough residual toner collection from high-density areas while applying appropriate processing to low-density areas.
Solution Approach 2:
The system implements localized processing strategies for different sub-data areas based on their dot population density characteristics. High dot population density areas receive enhanced residual toner collection, while low dot population density areas receive appropriate processing to prevent over-removal. This local quality approach ensures thorough residual toner collection where needed without unnecessarily complicating processing in other areas.
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 solution ensures consistent image quality by effectively managing toner distribution and preventing toner deterioration, reducing spoiled images and soiling, even when printing images with low dot population density.
Implementation Method 1
A developing roller rotates in contact with the photoconductive drum to supply toner to the electrostatic latent image to form a toner image
Implementation Method 2
the photoconductive drum is cleaned of residual toner by a cleaning unit
Implementation Method 3
A light emitting diode (LED) head illuminates the charged surface of the photoconductive drum to form an electrostatic latent image
Data Source
AI summary
A developing roller supplies toner to an image on an image bearing body, the image being formed in accordance with image data. A toner supplying member supplies developer material to the developer bearing member. A computing section computes a dot population density in corresponding one of a plurality of sub data areas. The plurality of sub data areas are obtained by dividing the image data such that the plurality of sub data areas are aligned in a printable area of a print medium in a direction perpendicular to the direction of travel of the print medium. A controller performs a developer material removing process based on the dot population density, in which the toner deposited on the developing roller is removed from the developing roller in an area corresponding to a low dot population density of image data.