Roll-to-Roll Electrode Inspection with Dual-Angle Defect Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current inspection methods for secondary battery electrodes manufactured by roll-to-roll apparatuses are inadequate in detecting surface defects, leading to performance degradation, low yield, and resource waste.
Innovation Solution
An inspection system comprising a pair of vision devices with a main illuminator and a sub-illuminator, a camera, and moving units to accurately detect surface defects on target objects, such as battery electrodes, by illuminating and imaging the objects with oblique light and adjusting positions for optimal defect detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional vision inspection method is used for battery electrodes, then the inspection process is simple, but the detection accuracy of surface defects is insufficient
Solution Approach 1:
The inspection system divides the lighting function into two separate illuminators: a main illuminator that provides oblique illumination to enhance surface defect visibility, and a sub-illuminator that provides supplementary lighting to fill shadows. This segmentation of the lighting system resolves the contradiction by creating a specialized multi-component illumination setup that dramatically improves defect detection accuracy while maintaining manageable system complexity through functional division.
Solution Approach 2:
The system applies different lighting qualities to different inspection needs: the main illuminator uses oblique lighting with specific angle control to highlight surface defects through shadowing effects, while the sub-illuminator provides diffuse supplementary lighting to illuminate shadowed areas. This local quality differentiation allows the system to achieve high defect detection accuracy without requiring overly complex unified lighting solutions.
2Measurement precision
If oblique illumination is used to enhance surface defect visibility, then detection accuracy improves, but shadow generation reduces image quality
Solution Approach 1:
The system converts the harmful shadow effect into a beneficial inspection mechanism. The main illuminator intentionally creates oblique illumination that generates shadows, which actually enhance the visibility of surface defects by creating contrast. The sub-illuminator then selectively fills in the shadows to provide balanced illumination. This approach transforms shadow from a harmful artifact into a useful contrast mechanism for defect detection.
Solution Approach 2:
The system controls the illumination parameters by adjusting the angle of the main illuminator to create optimal oblique lighting for defect visibility, while the sub-illuminator parameters are adjusted to provide supplementary lighting that fills shadows without creating new artifacts. This parameter control allows the system to maintain high surface defect visibility while minimizing shadow interference through precise lighting geometry management.
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 system effectively improves inspection accuracy by obtaining clear images of surface defects, preventing performance issues and resource waste by detecting defects before the laminating process.
Implementation Method 1
a main illuminator which obliquely emits light with respect to a normal plane of the guide roller to illuminate the target object
Implementation Method 2
a sub-illuminator which illuminates the target object by emitting light to remove a shadow generated by the main illuminator
Implementation Method 3
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
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A pair of vision devices (200) are supported by a base frame (100) while spaced apart from each other in a Y-axis direction, wherein each of the pair of vision devices (200) includes a main illuminator (211) which obliquely emits light with respect to a normal plane of a guide roller (11) to illuminate a target object (1), a sub-illuminator (212) which illuminates the target object (1) by emitting light to remove a shadow generated by the main illuminator (211), and a camera (213) disposed between the main illuminator (211) and the sub-illuminator (213). The X-axis moving unit (300) moves X-axis stages (310) with respect to Y-axis stages (410) in an X-axis direction so that the vision devices (200) move toward or away from the guide roller (11) while supported by the X-axis stages (310). The Y-axis moving unit (400) moves at least any one of the Y-axis stages (410) with respect to the base frame in the Y-axis direction to adjust a distance between the vision devices (200).