Optical system for precision inspection of flatness defects

In this paper, we present, full-field, and real-time precision scanning method of planes functional surfaces of components, for detection and measurement of flatness defects by optical way. This method consists of scanning the functional surface, with laser beam, witch vehicle a microscopic structure, then generating an interference pattern that highlights the shape defects present on all inspected surface. This optical system has a variable detection sensitivity that can be adapted according to the precision of component surface being inspected. This method, is used for precision measurement deformation in shape or absolute forms in comparison with a reference component form, of optical or mechanical components, where dimensions of inspected surfaces can range from two mm² to larger areas. The optical device used allows a significant dimensional surface magnification of up to 1000 times the area inspected for micro-surfaces, which allows easy processing and reaches an exceptional nanometric imprecision of measurements.