Image Forming Apparatus Shading Correction via Reference Member
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Solution Overview
Problem
Existing image forming apparatuses face challenges in maintaining high accuracy for print position stabilization due to fluctuations in temperature and other environmental factors, which affect the geometric characteristics and image density of printed images, leading to inaccuracies and reduced productivity during shading correction processes.
Innovation Solution
The image forming apparatus incorporates a system with CISs (Contact Image Sensors) that form adjustment images on both sides of the sheet, allowing for real-time and interruption adjustment modes to correct geometric characteristics and image density by analyzing the adjustment charts and updating image forming conditions, prioritizing shading correction to prevent skipping of adjustment chart readings and maintain high accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If shading correction is periodically executed to maintain detection accuracy, then print position accuracy is stabilized, but productivity is reduced due to interruptions in high-frequency printing operations
Solution Approach 1:
The system performs shading correction in advance by storing corrected data in a memory unit before high-frequency printing operations begin. This preliminary correction allows the printing system to maintain accuracy without interruptions during actual printing, as the correction data is already prepared and can be applied continuously.
Solution Approach 2:
The system creates a copy of the correction data by storing it in memory, allowing multiple printing operations to use the same corrected reference data simultaneously. This eliminates the need for repeated real-time corrections during high-frequency printing, maintaining both accuracy and productivity.
2Manufacturing precision
If real-time adjustment is performed by reading adjustment charts during printing, then geometric characteristics are corrected, but reading accuracy decreases due to temperature fluctuations and environmental factors
Solution Approach 1:
The system introduces a reference member with a reference surface as an intermediary standard for comparison. The image reading sensor reads both the adjustment chart and the reference surface, using the stable reference surface as a mediator to compensate for environmental fluctuations. This allows geometric characteristics to be corrected while maintaining reading accuracy despite temperature changes.
Solution Approach 2:
The system changes the reference parameter by using a reference surface with known, stable geometric characteristics as a baseline. By comparing adjustment chart readings against this stable reference and calculating deviation, the system can correct geometric characteristics while compensating for environmental parameter changes like temperature.
3Measurement precision
If the image reading sensor continuously monitors print position, then print position accuracy is stabilized, but the sensor is exposed to paper powder and dust that reduce detection accuracy
Solution Approach 1:
The system creates an optical copy of the adjustment image by reading it through the transparent guide member. This allows the sensor to acquire position information without direct contact with the printed surface, reducing exposure to paper powder and dust while maintaining measurement capability.
Solution Approach 2:
The transparent guide member serves as an intermediary medium between the sensor and the adjustment chart. It allows optical transmission for reading while protecting the sensor from direct exposure to harmful particles like paper powder and dust, thus maintaining both measurement precision and sensor reliability.
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 effectively stabilizes print position accuracy, suppresses fluctuations in geometric characteristics, and reduces productivity losses by ensuring accurate image formation and efficient shading correction, even during high-frequency printing operations.
Implementation Method 1
a line image sensor reads the image on the original conveyed on the image reading location, through the contact glass
Data Source
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Figure 2
Figure 3~4
AI summary
An image forming apparatus (101) includes an image forming unit (228) configured to form an image and a detection image on a sheet, wherein the detection image is used for detecting a geometric characteristics of an image to be formed on a sheet by the image forming unit (228); a fixing unit (229) configured to fix the image and the detection image formed by the image forming unit (228) on the sheet; a reading unit (231) configured to read the detection image on the sheet; a reference member (352,355); and a controller (222) configured to: adjust geometric characteristics of an image to be formed on a sheet based on a reading result of the detection image by the reading unit (231); and control the reading unit (231) to read the reference member (352,355) to execute shading correction based on a reading result thereof.