Multi-Color Ring Light for Solder Joint Segmentation
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Solution Overview
Problem
Conventional image processing methods struggle to effectively segment solder joints/pads made of the same material using ordinary visible light, making it difficult to evaluate the quality of workpieces.
Innovation Solution
A workpiece inspection method and apparatus utilizing a ring-shaped light source with multiple sub-light sources emitting different colors, which illuminates the workpiece's arc-shaped surface, allowing for clear image segmentation and quality evaluation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If ordinary visible light is used as a light source to capture the image of a workpiece, then the inspection system is simple and low-cost, but it is difficult to segment solder joints/pads made of the same material
Solution Approach 1:
The patent applies color changes by using a multi-color light source (red, green, blue LEDs) to illuminate the workpiece. Different materials reflect different colors of light differently, creating distinct color signatures in the captured image. This allows solder joints and pads made of the same material to be segmented based on their unique color reflection characteristics under multi-color illumination, resolving the segmentation difficulty while keeping the system relatively simple
Solution Approach 2:
The patent changes the illumination parameter from single-color (ordinary visible light) to multi-color (RGB LEDs) to improve segmentation accuracy. By changing the spectral composition of the light source, the system can differentiate between materials that appear identical under conventional lighting, achieving better measurement precision without significantly increasing device complexity
2Measurement precision
If a laser system is utilized to detect the height of each solder joint/pad, then the quality evaluation accuracy is improved, but the inspection cost increases and detection speed decreases
Solution Approach 1:
The patent replaces the mechanical/optical measurement system (laser) with an optical imaging system using multi-color LEDs and a camera. This substitution maintains quality evaluation accuracy through color-based material differentiation while significantly improving detection speed and reducing cost. The optical imaging approach captures all solder joints simultaneously in a single frame rather than measuring them sequentially with a laser
Solution Approach 2:
The patent uses inexpensive LED light sources and standard camera equipment instead of expensive laser systems. The LEDs are low-cost, long-living components that can be easily replaced if needed, providing a cost-effective alternative to laser-based inspection systems while maintaining sufficient measurement precision for quality evaluation
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 method enables accurate image segmentation and quality evaluation of workpieces by capturing images with distinct color regions, improving the precision and efficiency of the inspection process while reducing costs.
Implementation Method 1
Different ring-shaped sub-light sources may emit light of different colors
Implementation Method 2
a plurality of regions of different colors with obvious boundaries may appear on the arc-shaped curved surface
Data Source
Figure 1
Figure 2~3
Figure 4A~4B
AI summary
Disclosed is a workpiece inspection method including a step of using a ring-shaped light source to illuminate a workpiece to be inspected to capture an image of the workpiece, wherein, the workpiece has an arc-shaped curved surface facing the ring-shaped light source that contains plural ring-shaped sub-light sources arranged in sequence along a direction from being close to the workpiece to being away from the workpiece, and the plural ring-shaped sub-light sources emit light of different colors; a step of processing the captured image to obtain plural image regions, wherein, the plural image regions have different colors, and the colors of the plural image regions correspond to the colors of the light emitted from the plural ring-shaped sub-light sources; and a step of inputting image feature parameters of the plural image regions into a predetermined workpiece quality inspection model to attain a quality inspection result of the workpiece.