Image Processing Device Correcting Long Period Density Unevenness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for correcting density unevenness in the sub-scanning direction of print devices are inadequate for addressing long period density unevenness, as they rely on data from a single sheet of recording paper, which cannot capture periodic variations caused by longer components like intermediate transfer belts and fixing heater timing.
Innovation Solution
An image processing device that successively prints test images on multiple sheets of recording paper, analyzes the density profiles arranged according to sheet intervals, and prepares correction data to remove long period density unevenness, while also detecting and correcting short period unevenness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If density unevenness is measured using only one sheet of recording paper, then the measurement process is simple and quick, but long period density unevenness cannot be detected
Solution Approach 1:
The measurement process is segmented into multiple sheets of recording paper, where each sheet captures a portion of the density profile. By dividing the measurement across multiple sheets, the system can detect long period density unevenness that spans beyond a single sheet while maintaining efficient measurement through parallel processing of multiple sheets.
Solution Approach 2:
The measurement approach transitions from a single-dimension (one sheet) to a multi-dimensional approach by stacking multiple sheets in the sub-scanning direction. This dimensional extension allows the system to capture periodic density variations that occur over lengths greater than one sheet, enabling detection of long period density unevenness without significantly increasing measurement time.
2Measurement precision
If test images are printed on multiple sheets of recording paper, then long period density unevenness can be detected, but the measurement and analysis process becomes more complex
Solution Approach 1:
The system performs preliminary actions by pre-aligning and pre-processing the density profiles from multiple sheets before conducting the actual analysis. By preparing the data in advance and organizing it according to sheet intervals, the system reduces the complexity of the subsequent analysis process while maintaining the ability to detect long period density unevenness.
Solution Approach 2:
The system introduces an intermediary processing step that involves arranging density profiles from multiple sheets in a specific order corresponding to sheet intervals. This intermediary organization acts as a bridge between the raw multi-sheet data and the final analysis, simplifying the detection process by structuring the data in a manner that naturally reveals periodic patterns.
3Productivity
If only short period density unevenness is corrected, then correction is simple and fast, but long period density unevenness remains uncorrected
Solution Approach 1:
The correction system dynamically adapts to different periodicities by analyzing the density profiles from multiple sheets and automatically identifying both short period and long period density unevenness patterns. This dynamic approach allows the system to apply appropriate correction for each detected pattern, achieving comprehensive density uniformity without sacrificing correction speed through automated pattern recognition and adaptive correction application.
Data Source
AI summary
Disclosed is an image processing device including: a sample output unit to instruct a print device to successively print test images on a plurality of sheets of the recording paper; a profile preparing unit to prepare a plurality of profiles of the density unevenness in the sub-scanning direction in the plurality of sheets of the recording paper, from measuring data obtained by optically reading the test images; an analyzing unit to analyze the profiles by arranging the profiles in a printing order apart from each other so as to correspond to intervals of the sheets of the recording paper, and to detect a long period density unevenness in the sub-scanning direction, which has a long period extending through the plurality of sheets of the recording paper; and a correction data preparing unit to prepare correction data for removing the long period density unevenness.