Of all the hardware components that constitute a vision system, illumination is the most crucial. Proper lighting is essential in order to achieve accurate inspection results and minimize the number of false rejects. Most vision inspection machines on the market utilize white or monochrome (typically red) LED illuminators and the output of each light source can be adjusted to emphasize flaws in the object.
However, this approach is inadequate for the detection of subtle defects on O-rings or gaskets, particularly those with reflective surface finish, because it creates insufficient image contrast to reliably detect these flaws. In order to overcome this limitation, UTPVision developed and patented Color Vision, a multi-color lighting solution, that makes possible to highlight very subtle surface defects that are extremely difficult to identify with traditional white or monochrome illumination.
Example of a critical surface defect on the side of an O-ring: with UTPVision’s dual color illumination system, the small unfilled region is highlighted enough for the vision system to detect it (blue pixelated area).
By combining two different color light sources (red and green) coming from different angles and color cameras, it is possible to leverage chromatic separation to strongly emphasize small surface discontinuities and to achieve significantly more accurate and reliable inspection results.
This solution can be successfully applied to the inspection of any surface of the sample, with simple adjustments to the incidence angle of each light source.
|As a further step in the continuous development of more advanced lighting solutions, UTPVision recently upgraded the patented 2-color illumination system to a 4-color version (red/green/blue/yellow), giving seal manufacturers even more flexibility for the inspection of different color O-rings, gaskets or other parts.|