Roll-to-Roll Electrode Inspection With Shadow-Removing Illumination
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Solution Overview
Problem
Existing manufacturing processes for secondary batteries, such as lithium-ion polymer batteries, face challenges in accurately detecting defects in electrode assemblies, leading to performance degradation, resource waste, and environmental pollution.
Innovation Solution
An inspection system for roll-to-roll apparatuses that includes a base frame, pair of vision devices with main and sub-illuminators, and a camera to detect surface defects in battery electrodes, utilizing X-axis and Y-axis moving units for precise alignment and shadow removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single illuminator is used to inspect the target object, then the device complexity is reduced, but the measurement precision deteriorates due to shadow generation
Solution Approach 1:
The illumination system is segmented into multiple independent illuminators (first illuminator and second illuminator) positioned at different locations. Each illuminator independently illuminates the target object from different angles, allowing the system to capture multiple images that can be processed to eliminate shadow effects and improve defect detection accuracy.
2Measurement precision
If multiple vision devices are used to inspect the target object, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
Multiple vision devices are merged into a coordinated inspection system where each device captures images from different perspectives. The images from multiple vision devices are combined and processed together to eliminate shadows and improve defect detection accuracy, while sharing common control and processing resources.
3Measurement precision
If the vision devices are positioned closer to the target object, then the measurement precision is improved, but the shadow effect worsens
Solution Approach 1:
The illuminators are positioned asymmetrically relative to the vision devices and target object. The first illuminator is positioned at a first location and the second illuminator at a second location, creating asymmetric illumination paths that allow light to reach shadowed areas from multiple angles, thereby reducing the shadow effect while maintaining high image quality.
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
Enhances the accuracy of defect detection in battery electrodes, improving yield and reducing waste by identifying issues like foil exposure before the laminating process.
Implementation Method 1
a camera disposed between the main illuminator and the sub-illuminator to obtain an image from light reflected by the target object illuminated by the main illuminator and the sub-illuminator
Implementation Method 2
a sub-illuminator which illuminates the target object by emitting light to remove a shadow generated by the main illuminator
Data Source
AI summary
A pair of vision devices are supported by a base frame while spaced apart from each other in a Y-axis direction, wherein each of the pair of vision devices includes a main illuminator which obliquely emits light with respect to a normal plane of a guide roller to illuminate a target object, a sub-illuminator which illuminates the target object by emitting light to remove a shadow generated by the main illuminator, and a camera disposed between the main illuminator and the sub-illuminator. The X-axis moving unit moves X-axis stages with respect to Y-axis stages in an X-axis direction so that the vision devices move toward or away from the guide roller while supported by the X-axis stages. The Y-axis moving unit moves at least any one of the Y-axis stages with respect to the base frame in the Y-axis direction to adjust a distance between the vision devices.