Optical digital spherometer based in structured light perfilometry

In this work, it is present a spherometer based in grating projection techniques and phase evaluation. The optical setup1 consists in a projector with a Ronchi ruling and a CCD camera interfaced with an image processor. The CCD camera registers the images of the fringe-pattern as modulated by the object curvature and purposely-developed software digitally processes these images. The object profile is reconstruct using phase evaluation methods3 (PEM): Particularly, were used the Fast Fourier Transform (FFT) algorithm and phase stepping algorithms. With the resulting values and using the sagitta calculation the average radius of curvature can be evaluated in any point on the object surface © 2001 SPIE · 0277-786X/01/$15.00.