Application Advantages of Machine Vision for Appearance Quality Inspection

During the production process of products, the surface quality defect detection of products is usually carried out by traditional manual detection methods.

Machine vision detection technology

With the development of science and technology, especially research in computer technology, a new technology called machine vision detection technology has emerged. Systems designed with this new technology are not affected by harsh environments and subjective factors. They can quickly and accurately detect the quality of products and complete high-intensity detection work that cannot be performed manually.

Machine vision detection incorporates knowledge from different domains such as computer technology, data construction, image processing, pattern recognition, and software engineering.

Machine vision systems

A typical machine vision system should include five main components: light source, lens, camera, image acquisition card, and visual processor.

Surface defect detection of objects is a typical application of machine vision. Taking scratch detection on socket panels as an example, images are acquired by using LED ring lights for direct dark field illumination. Then, dynamic threshold segmentation is applied to extract the interested regions in the socket panel area for scratch detection. Morphological operations are used to remove noise and small protrusions in the segmented area using region features and morphology, ensuring sufficient accuracy. After that, algorithms such as radiation transformation, image smoothing, and connected area extraction are applied.

The directionality of the lighting in the machine vision system usually has two types: diffuse and direct illumination. When diffused, the intensity of light is almost the same in all directions. When directly illuminated, the light emitted by the light source is concentrated in a narrow space. If the detection object is a scratch on a socket panel, under bright field illumination, it is difficult to obtain an ideal scratch image due to the small area of the detection and the non-obvious scratches. Therefore, LED ring lights, a kind of illuminator machine, are used for direct dark field illumination, and the ring light and the surface of the object are at a small angle to highlight the cracks and protrusions. Therefore, scratches, textures, or carved text are enhanced, and images are clearer.

Intelligence, automation, digitalization, and informationization are the development trends of future manufacturing industries.

Canrill Optics is the first company in China that focuses on the manufacturing, marketing, and design of eccentric lenses. It is also the only company with a complete industrial lens supply chain that owns its mechanical and optical factories. As a custom-made lens manufacturer, Canrill Lens has undergone four generations of advanced technology and performance upgrades, winning the trust of customers worldwide, including Samsung, Apple, LG, Huawei, Dajia Laser, and TSMC. 

We firmly believe that through continuous efforts and innovation, we can achieve win-win cooperation with our customers. If you have any relevant requirements, please contact us.