Structure: like below picture, the low angle illumination can prevent the lighting to reflect back to lens on the even surface, and the brightness is not strong, when the lighting is on the uneven surface, the reflective light is disorder, and some of lighting comes into lens, and the brightness is higher.
Main application: Surface scratch, printed letter inspection and recognition, foreign part inspection on the surface, edge size measurement, location, angle measurement, stamping letters and images inspection and recognition and so on.
Advantage: Easy installation and stable image result
Disadvantage: It is not very good for transparent and edge scratch object inspection, under some special situation, it requests the low angle ring light under certain working distance to get good image result.
LED machine vision light: bar light, line scan light, low angle ring light and so on
Dark field, low angle light image result of coin
Low angle light can make the background dark, what we usual said dark illumination, it can show the slope information from 45°to 60°clearly, like the scratches, stamping letters on the surface.
Low angle light image result