Image Forming Apparatus Dynamic Resolution Control for Moiré Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The image forming apparatus faces a deterioration in correction accuracy due to the difference in color values between the front-surface and rear-surface reading units, caused by the lower resolution of the rear-surface reading unit and the higher image printing resolution, leading to moiré occurrence when reading high-definition chart documents.
Innovation Solution
The apparatus includes a setting unit that adjusts the printing resolution to match or be lower than the threshold of the rear-surface reading unit, printing a correction image with this adjusted resolution to accurately determine and correct color value differences between the two reading units, thereby preventing moiré occurrence and improving correction accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the image printing resolution is set higher than the reading resolution of the rear-surface reading unit, then high definition image printing is achieved, but moiré occurs when reading high-definition chart documents, deteriorating correction accuracy
Solution Approach 1:
The patent applies dynamics by making the printing resolution adjustable rather than fixed. The control unit dynamically selects the printing resolution based on the type of document being processed. For chart documents, it selects a resolution that prevents moiré occurrence, while for other documents it may use higher resolutions. This dynamic adaptation resolves the contradiction between achieving high printing quality and preventing moiré that deteriorates correction accuracy.
Solution Approach 2:
The patent changes the parameter of printing resolution according to the document type. By detecting whether the document is a chart document and adjusting the printing resolution parameter accordingly, the system prevents moiré occurrence while maintaining correction accuracy. This parameter change allows the system to optimize both printing quality and measurement precision for different scenarios.
2Ease of manufacture
If a rear-surface reading unit with lower resolution is used, then cost is reduced, but correction accuracy deteriorates when reading high-definition chart documents
Solution Approach 1:
The patent changes the operating parameters of the rear-surface reading unit by adjusting the printing resolution before reading. For chart documents, it sets the printing resolution to a level that prevents moiré occurrence, ensuring that the lower-resolution reading unit can still accurately read the chart without introducing moiré artifacts. This allows cost reduction through using a lower-resolution reading unit while maintaining correction accuracy through parameter optimization.
3Manufacturing precision
If the printing resolution is set high for high definition printing, then image quality is improved, but the difference between color values from front-surface and rear-surface reading units cannot be accurately determined
Solution Approach 1:
The system dynamically adjusts the printing resolution based on the document type. For chart documents, it selects a resolution that ensures accurate color value determination by preventing moiré, while for other documents it may use higher resolutions for better image quality. This dynamic selection allows the system to optimize both image quality and measurement precision according to the specific task requirements.
Data Source
AI summary
An image forming apparatus includes a first reading unit configured to read a first image on a first surface of a document, a second reading unit configured to read a second image on a second surface of the document different from the first surface, a printing unit configured to print a third image on a sheet, and a setting unit configured to set resolution of the third image printed by the printing unit. The printing unit prints the third image on the sheet with the resolution set by the setting unit. The printing unit also prints a fourth image with resolution lower than or equal to a threshold, without using the set resolution, the fourth image used for correction of at least a color value obtained by reading the second image using the second reading unit.