Machine Vision Systems- The Importance of Lighting

Machine vision systems are critical components of quality control processes throughout manufacturing. They provide crucial inspections and measurements that must be both accurate and repeatable. Environmental variables will affect the performance of the imaging system. Frequently overlooked is the importance of having consistent lighting within the system.

Machine vision systems do not assess the object itself but rather the image of the object. Therefore it is imperative to get the correct lighting arrangement for the application. This will allow the camera to capture all image details necessary to make accurate measurements. Information that is completely missing from the image can never be recovered by analysis algorithms. The image is influenced surface characteristics, the wavelength of the light and the direction of the light. A number of lighting configurations including back lighting, bright field or dark field illumination and the use of diffuse and dome illumination have been developed to solve these challenges. However, getting the correct illumination configuration is only the initial part of the solution. Ensuring that the lighting remains consistent over time is essential to making repeatable measurements.

Lighting can gradually be impacted by a number of factors such as:

  • The age of the light
  • The temperature of the light
  • The stability of the power supply
  • Changes in ambient light
  • Synchronization of pulsed lighting and camera exposure
  • Physical position of the light

A properly functioning vision system depends on cameras, lights and analysis algorithms all working at peak efficiency. Machine Vision Systems must be maintained and should be “tuned up” on a regular basis. If your system is not performing as it used to or as you require, protect your investment and improve quality control by contacting AS&E to schedule a service call.