Machine vision systems or visual inspection machines provide accurate part inspection with the help of high-quality images. An ideal way of achieving this accuracy is to optimize the part lighting that you want to be inspected.
With proper lighting, it’s easier to maximize the contrast, which makes it easier for the camera to identify a specific surface, mark, or shape. On the other hand, poor lighting doesn’t illuminate all of the part, which adds to the total processing time. Read on to know more.
1: Bright Lights
Another role of a machine vision system is to identify missing material in the part being inspected. Also, the system can also find out if there is insufficient amount of material in the mould, which is called a short shot.
For better detection of the short shots, today’s manufacturer’s make use of a special illuminator called a Nerlite DOAL.
2: The Wavelength
Often, manufacturers use this technology to ensure the correct orientation of the components on the circuit board, especially an integrated circuit board.
If the chip is oriented properly, its copper side will be down for proper connection. Also, the chips get flipped during the process of assembly, which may cause assembly failure.
3: Non-Diffused Light
It’s difficult to see tiny cracks in materials that are transparent like glass. In hundreds of glass containers, it’s even harder to detect tiny cracks.
Therefore, non-diffused light is used for better detection of the cracks. This helps reduce waste and customer complaints.
4: Diffuse Light
The detection of inaccurate, damaged or missing content can help the manufacturers of drug improve the medicine quality. But the use of bright light and prevent reflections at the same time is difficult.
If the light sources are single-plane or unidirectional, they may cause shadows and reflections. But with diffused light, it’s possible to illuminate the object from different sides and prevent reflections.
5: Color for Contrast
Regardless of the type of application, we can’t deny the importance of high-contrast images. An easy of achieving this goal is to use colored light. The wavelength of the light can make the part features look dark or bright to the camera, especially to the monochrome camera.
If you want to make the features look dark, you can opt for the opposite color. However, if you opt for the same color light, it will make the features look lighter in color.
6: Strobed Light
For accurate inspection of fast-moving parts, a strobed light is used. With a non-strobe light, it’s not possible to capture images that are free of noise. In this case, it’s better to opt for a strobed light only.
Also, the strobe light should have proper pulse duration for producing high-quality images. Typically, the pulse duration is equal to the time the part image takes to cover a distance.