Patent ID: 9347771
Filing Date: 2016-05-24
CPC Classification: G01B

Claim Text:
1. A spherical shape measurement method for measuring a surface shape, the method including: freely rotating a sphere to be measured; measuring a partial spherical shape of each measurement area, which is established so as to have an area overlapping with another measurement area adjacent to each other, at each rotation position; and joining the partial spherical shapes of the measurement areas by a stitching operation based on a shape of the overlapping area, thereby measuring the surface shape, the method comprising the steps of: enabling the sphere to be re-held at a different position; and separating a positional displacement between half parts of the sphere before and after re-holding, which is caused by an effect of an error owing to the re-holding of the sphere, into three rotational components, performing quantification of magnitudes of the three rotational components by image correlation, correcting the positional displacement, and thereafter performing the stitching operation to measure entire part of sphere surface.