EVT Eye Vision Technology GmbH Product
Concerning image processing the choice of the right illumination is essential. The sentence "Good illumination, good machine vision" should be a reason to think thoroughly about the right illumination for the machine vision task ahead. With the EyeLight series for example, EVT has innovative industrial lighting for almost every application. Therefore also a selection of dark-field illumination, such as the EyeLight LLA series. These are available as RGB model or in their separate colors: red, green, blue or white. The dark-field ring lights are available in different inner- and outer-diameters. The inner-diameters vary from 40 to 136 mm and the outer-diameters vary from 74 mm to 174 mm. The LLA series is very compact, with only 20 mm of body height. It works best with working distances ranging form 5 to 10 mm. Optionally there are also diffusion filters and polarization filters available. The rays of the dark-field illumination are refracted from the object. Therefore not all light rays reach the camera lens directly. Typical applications for dark-field illuminations are edge detection and the inspection of embossed imprints or errors such as scratches on metal or other shiny surfaces. The advantage of the LLA dark-field ring light is that reflections are avoided. With the flat angle of reflected the light is ideal for applications of slightly uneven surface structures or engravings on metal surfaces, etc. The uneven surfaces and edges of a coin or a button cell are illuminated clearly as well as scratches on the surface.