摘要 |
In machining such as lapping and polishing, the detection of interference fringes is carried out during the machining, and an interference fringe image of a size sufficient to determine the surface profile is obtained. The workpiece is mounted on a machining mechanism base, and a lapping tool mounted on the workpiece is rotated. The lapping tool has a measurement window and an interferometer is provided above the workpiece via the lapping tool. The interferometer captures plural interference fringe images at different positions of the measurement window, each including fringe images of the measurement window areas and shadow images of the areas obstructed by the lapping tool. The shadow images are eliminated from the interference fringe images on the basis of the reference value for the optical intensity of the shadow image, and the fringe images of the measurement window areas are synthesized to form consecutive synthesized interference fringe images for a wide range of interference fringes.
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