Structured light in visual inspection

When a processed part is visually inspected along a projected line of several meters in length, generated by adequate cylindrical optics, the gaussian beam intensity profile along line length will create problems given by the fading edges of the intensity profile, the variation of the light level across the line and the presence of `hotspot' in the center of the line. In order to avoid these problems, we used the structured light generated by a special developed laser diode producing a non- gaussian (evenly illuminated) distinct line. The visibility of the projected line in real working conditions, depth of field and focusing performances of the beam are presented, as they have been evaluated.