Scanner Shading Correction Using Marked Reference Plate
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Solution Overview
Problem
Conventional scanners face challenges in performing effective shading correction when a mark is made on the reference plate, leading to inadequate image correction due to variations in light transmission and lens performance.
Innovation Solution
A scanner with a marked reference plate and a calculation section that compares read data with stored reference data to calculate shading data, using formulas to offset and average values to match phase and adjust for lens irregularities, ensuring suitable shading correction even with a mark present.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a mark is made on the reference plate, then the reference plate can be used for skew detection and document size matching, but shading correction of image sections corresponding to the mark cannot be suitably performed
Solution Approach 1:
The reference plate is divided into a marked region (for skew detection and size matching) and unmarked regions (for accurate shading correction). By segmenting the reference plate into functional zones, the patent enables both skew detection capability and accurate shading correction to coexist without interference.
Solution Approach 2:
Different regions of the reference plate are assigned different properties: the marked region contains the mark for skew detection, while unmarked regions maintain uniform reflectivity for accurate shading correction. This local differentiation allows each region to serve its specific function optimally.
2Extent of automation
If read data of the marked reference plate is used as shading data, then the marking function is utilized, but variation in output from light receiving elements cannot be properly corrected
Solution Approach 1:
The patent extracts the mark detection function from the shading correction function. The mark is separated as a distinct feature used only for skew detection and document size matching, while shading correction relies on unmarked regions of the reference plate. This extraction eliminates the conflict between mark presence and shading correction accuracy.
Solution Approach 2:
The patent introduces an intermediary approach by using unmarked regions of the reference plate as the basis for shading correction, while the marked region serves as a separate reference for skew detection. This intermediary unmarked region acts as a mediator that enables both functions to operate independently and effectively.
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
The solution allows for accurate shading correction of images by configuring shading data to resemble pre-mark conditions, effectively addressing the issue of mark-induced errors in image processing.
Implementation Method 1
a plurality of lenses that guide reflected light of reading light radiated onto the document to each light receiving element
Data Source
AI summary
A scanner includes a marked reference plate in which a mark is made on a reference plate, and a non-volatile memory that stores reference data, which is a result of the reference plate disposed facing an image reading sensor being read by the image reading sensor, in which read data is acquired a result of the marked reference plate being read by the image reading sensor, and shading data is calculated by comparing the read data and the reference data.