Inclined Backing Surface for Image Reading Edge Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image reading apparatuses face challenges in accurately detecting the edges of sheet-like media due to variations in shadow density caused by medium thickness, leading to decreased detection accuracy, especially for thin media where shadows are not noticeable.
Innovation Solution
An image reading apparatus is designed with a backing surface inclined relative to the conveyance direction and a gap between the conveyance path and the backing surface decreasing from the light source to the imaging unit, forming a prominent shadow on the backing surface to enhance edge detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a shadow-based edge detection method is used, then edge detection can be performed, but detection accuracy decreases for thin media due to shadow density variations
Solution Approach 1:
The backing surface is designed with a specific inclination angle (α) relative to the conveyance path, creating a localized geometric configuration that enhances shadow formation. This local structural quality ensures that shadows are consistently formed with appropriate density across different media thicknesses, particularly improving detection for thin media where shadow density variations previously caused accuracy problems
Solution Approach 2:
The invention changes the geometric parameter of the backing surface from a conventional parallel arrangement to an inclined arrangement at angle α. This parameter change transforms the shadow formation characteristics, ensuring that shadows are projected with consistent density regardless of media thickness, thereby resolving the reliability issue for thin media detection
2Measurement precision
If the backing surface is parallel to the conveyance path, then the structure is simple, but shadow formation is insufficient for accurate edge detection
Solution Approach 1:
Rather than making the entire backing structure complex, the invention applies a specific inclination angle α only to the backing surface portion that contacts or approaches the media. This localized geometric modification achieves improved shadow formation without requiring complex overall device architecture
Solution Approach 2:
The invention introduces a angular dimension (inclination angle α) to the previously planar parallel arrangement of the backing surface. By adding this dimensional parameter, the system achieves superior shadow formation capability while maintaining relatively simple structural implementation
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 configuration improves edge detection accuracy by suppressing shadow density variations and ensuring a noticeable shadow, even for thin media, allowing for precise edge detection regardless of medium size or position.
Implementation Method 1
a shadow of the medium is formed on the backing surface due to light from the light source
Data Source
AI summary
An apparatus includes: a light source opposite to one surface of a medium; a backing member opposite to another surface of the medium and including a backing surface opposite to the another surface of the medium; an imaging unit opposite to the one surface of the medium and at a position different from the light source in a conveyance direction, and to pick up an image of the medium and the backing surface on which a shadow of the medium is formed due to light from the light source; and a processor to generate image data including the image of the medium and the backing surface based on a result by the imaging unit, wherein the backing surface is inclined with respect to the conveyance direction, and a gap between the path and the backing surface decreases from a light source side toward an imaging unit side.