The Right Lighting for Machine Vision Applications

lighting for machine vision applicationsLighting is a key component in machine vision applications. If your lighting system is not the right one, then your machine vision system may not deliver the reliable data you require.

Different Types of Machine Vision Lighting    

Having the right machine vision lighting is paramount to ensuring data capture is effective and reliable. Along with environmental factors, the object being viewed will determine the approach that is best for your application.

Machine vision lighting options common in industrial applications include:

  • Polarized Lighting – helps cut down light coming from other sources, working just like a pair of sunglasses.
  • Diffuse Dome Lighting – eliminates hot spots in lighting, making it perfect for curved parts.
  • Bright Field Lighting – bright light is directed right at the object of inspection, highlighting any defects, particularly on smooth surfaces.
  • Dark Field Lighting – dim light is shown at a low angle and any defects on the part will cast a shadow.

You may require a combination of these types of lighting, depending on your space, the surface and shape of the object being inspected, the set-up of your inspection system and a whole host of other considerations that need to be made.

Machine Vision Lighting Challenges to Consider

For a variety of cost and practicality reasons, LED lights are the primary light source for machine vision system applications. As with any system, there are challenges to consider.

  • Temperature – LED lights are affected greatly by temperature. This is crucial in industrial applications with rugged environments. Between 25 – 90°
  • Power – LED output is proportional to the incoming current. Variations in power supply can affect the consistency of machine vision lighting systems.
  • Age – LEDs are reliable but as they age, they get dimmer.
  • Ambient Light – Most machine vision systems can compensate for ambient light, however, ambient light is likely to change and this can interfere with brightness levels in machine vision.
  • Pulsing Errors – In some high-speed applications, it’s necessary to use a pulsing LED light. Sometimes, the timing of the camera and pulsing will become out of sync, quickly deteriorating the quality of the images.

There is an equally practical and cost effective solution for all of the above challenges to ensure the benefits of LED lighting are fully realized. For example, there are current controllers to ensure there are no variations in power that effect the intensity of the light due to aging LEDs or inconsistencies in power current.

Machine vision lighting is an integral component of a machine vision system. It helps the image capture device to deliver optimal results. The wrong lighting affects the reliability of data capture. The right lighting is needed to ensure reliability and repeatability of your inspection system.

For more information about machine vision lighting, reach out to one of our vision system integrators via our free Ask the Experts resource at Vision Online.