What type of lighting is used in machine vision?

Types of Lighting Used in Machine Vision

Machine vision systems rely heavily on lighting to enhance the contrast of features of interest, improving the accuracy and reliability of the vision inspection process. There are several types of lighting commonly used in machine vision:

1. Backlighting

Backlighting illuminates the object from behind, creating a sharp silhouette. This type of lighting is useful for measuring external dimensions and detecting the shape of objects.

2. Bright Field Lighting

Bright field lighting involves placing the light source directly in line with the object to highlight the surface defects and topography. It typically generates a high-contrast image revealing surface textures and imperfections.

3. Dark Field Lighting

Dark field lighting angles the light source at a low incident angle to the object. This set-up is excellent for highlighting surface flaws like scratches or pits by reflecting light off the imperfections while keeping the rest of the surface in shadow.

4. Diffuse Lighting

Diffuse lighting provides even illumination to minimize shadows and reflections. It is particularly beneficial for imaging highly reflective or curved surfaces.

5. Structured Lighting

Structured lighting uses light patterns such as grids or stripes to quantify three-dimensional shapes. The distortion of the pattern on the object's surface allows depth and contour to be calculated using sophisticated imaging techniques.

6. LED Lighting

LED lights are prevalent in machine vision due to their long lifespan, range of colors, and intensity levels. They are versatile and can be used in different configurations to suit a broad spectrum of applications.

Each lighting type offers specific advantages, depending on the applications and characteristics of the object being inspected. Choosing appropriate lighting is crucial in maximizing the system's performance.