Image Density Correction via Target Tone Data in Printers
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Solution Overview
Problem
Existing image forming apparatuses face challenges in maintaining image quality during continuous printing on multiple sheets, as failures in reading tone patterns can lead to incomplete image density correction, resulting in uneven image densities and decreased productivity.
Innovation Solution
The image forming apparatus includes an image forming unit, an image reader, and a controller that forms and reads images for adjustment, determines target data based on these readings, and adjusts image forming conditions accordingly. Additionally, the controller re-forms the first image if the image reader fails during a job and avoids adjusting conditions based on the second image if its reading fails.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the image forming apparatus periodically corrects image density by creating and reading adjustment charts during continuous printing, then image quality uniformity across multiple sheets is improved, but productivity decreases when reading failures occur requiring re-creation of adjustment charts
Solution Approach 1:
The system creates a first adjustment chart at the start of a job to establish target tone data before printing begins. This preliminary action ensures that even if subsequent periodic readings fail, the target reference is already established, preventing the need to stop and recreate it.
Solution Approach 2:
When the image reader fails to read a tone pattern, the system uses the previously stored target tone data as a copy/reference instead of requiring immediate re-creation of the adjustment chart. This allows the printing process to continue without interruption while maintaining image quality correction capabilities.
2Manufacturing precision
If the image forming apparatus determines target tone at the start of a job based on reading a tone pattern, then image density correction can be performed during the job, but if the reading fails at this stage, the first N sheets cannot have their image quality maintained
Solution Approach 1:
The system attempts to read the tone pattern multiple times at the start of a job before giving up. This beforehand cushioning approach increases the probability of successfully establishing target tone data, ensuring that image quality correction can begin as early as possible in the job.
Solution Approach 2:
The system establishes target tone data at the start of the job through preliminary reading attempts. Once successfully established, this target data serves as a reference for all subsequent image density corrections throughout the job, ensuring consistent image quality from the first sheet onwards.
3Manufacturing precision
If the image forming apparatus re-reads the tone pattern when reading fails during image density correction, then image quality maintenance is improved, but productivity decreases due to repeated correction cycles
Solution Approach 1:
The system dynamically adjusts its correction strategy based on reading success. When reading succeeds, it performs immediate correction. When reading fails, it skips correction for that cycle and continues printing, adapting the correction frequency to actual reading performance rather than following a rigid periodic schedule.
Solution Approach 2:
When the current tone pattern reading fails, the system uses the previously stored target tone data as a reference copy to maintain correction capability without requiring immediate re-reading, allowing the printing process to continue at full speed while preserving image quality control.
Data Source
AI summary
An image forming apparatus includes an image forming unit configured to form an image on a recording medium based on an image forming condition; an image reader configured to read an image for adjustment of the image forming condition, the image for adjustment being formed on the recording medium; and a controller configured to control the image forming unit to form images for adjustment; control the image reader to read the images for adjustment; determine target data based on a reading result of a first image included in reading results of the images for adjustment; and adjust the image forming condition, during execution of a job in which the image forming unit forms a plurality of images on a plurality of recording mediums, based on the target data and a reading result of second image included in the reading results of the images for adjustment.