In machine vision systems, light source is one of the key factors affecting imaging quality and detection accuracy. Efficient light source configuration can greatly improve the system’s recognition accuracy, making automated detection, classification and guidance more reliable. Therefore, choosing the right machine vision light source is crucial to achieving stable and accurate visual inspection.

What is machine vision light source? Machine vision light sources are artificial light sources used to improve the imaging quality of target objects. They increase image contrast and highlight defects or target features by adjusting the intensity, angle, and wavelength of light. In machine vision applications, light sources help eliminate external environmental interference and ensure imaging stability and consistency. Whether it is detecting surface defects of products, measuring dimensions, or precise positioning in industrial automation processes, light sources play a vital role.

Common light source types Depending on the application scenario and detection requirements, different types of light sources can be used to achieve the best effect. The following are common light source types and their characteristics in machine vision:

1. Ring light A ring light is a uniform surrounding light source, usually installed around the camera. It eliminates shadows and provides uniform lighting, suitable for the detection of reflective or transparent objects. It can effectively reduce the reflection interference of light and is often used in surface detection and character recognition.

2. Coaxial light source Coaxial light source projects light vertically onto the object to be inspected through optical components, which is suitable for the inspection of high reflectivity or smooth surfaces. It can reduce the interference of reflected light and highlight small surface details. It is often used in high-precision manufacturing fields such as semiconductors or glass.

3. Backlight The backlight illuminates the object from behind, forming a clear outline image for size measurement, shape detection and edge recognition. It can significantly increase the contrast between the target and the background and is suitable for precise edge detection applications.

4. Point light source Point light source is used to focus the lighting on a specific area, suitable for detecting tiny surface defects or highlighting local details. This light source can magnify defects or features by locally highlighting the target object.

5. Multispectral light source Multispectral light source can emit light in multiple wavelength ranges (including ultraviolet light, visible light, infrared light, etc.), which is suitable for applications that need to distinguish different materials or detect invisible light spectrum. This type of light source is often used in food inspection, agricultural automation, and medical applications to provide characteristic information of different substances.

How to choose a suitable light source? Selecting the proper lighting is critical to the success of a machine vision system. The following points are key considerations in the selection process:

1. The reflective properties of the object It is very important to choose the light source according to the surface material of the object being tested. For highly reflective materials, a coaxial light or ring light can effectively eliminate excessive reflections, while for transparent objects, a backlight is ideal.

2. Detection targets Different detection targets require different light sources. For example, if surface texture needs to be emphasized, a point light source can bring out the details, while if dimension measurement or shape detection is required, a backlight source will provide a clear outline image.

3. Light source wavelength The wavelength of the light source will affect the imaging results. Infrared light can penetrate some surface layers, revealing hidden details, while ultraviolet light can enhance the reflective properties of certain materials. Selecting a light source with an appropriate wavelength according to detection requirements can significantly improve the detection effect.

4. Ambient light interference In industrial environments, external light interference is often a major challenge for detection systems. Selecting a light source that provides stable illumination and using appropriate shielding techniques to isolate ambient light can ensure stable image quality.

Future development trend of machine vision light sources With the advancement of technology, the development of machine vision light sources will become more and more intelligent. Here are some future trends:

Intelligent light source adjustment
The new generation of light sources will be more intelligent and can automatically adjust the brightness and wavelength according to changes in the detection scene to adapt to different application requirements. This will improve the flexibility of the detection system and reduce reliance on manual adjustments.

Low power consumption and green light source
Energy conservation and environmental protection have become an industrial trend. Future light sources will pay more attention to low power consumption design while maintaining high brightness and stability.

Hyperspectral imaging technology
Hyperspectral imaging technology can capture information over a wider range of wavelengths, allowing inspection systems to identify more subtle material characteristics. This technology will become more and more popular in high-precision industrial inspection.

in conclusion
The importance of light source in machine vision systems cannot be ignored. Selecting a suitable light source according to detection requirements can not only improve detection accuracy, but also enhance the stability and reliability of the system. With the advancement of technology, light source technology is also constantly evolving. The future intelligent light source will bring higher flexibility and efficiency to machine vision inspection.