METHOD AND INSTRUMENT FOR MEASURING THREE-DIMENSIONAL SHAPE AND NORMAL VECTOR OF OBJECT HAVING MIRROR SURFACE

摘要

PROBLEM TO BE SOLVED: To provide a method by which the three-dimensional shape and normal vector of an object having mirror surface can be measured simultaneously with high accuracy. ;SOLUTION: An optical path, through which a laser beam is perpendicularly projected upon a mirror finish object from the top side by means of a mirror 3 is switched to another optical path, through which the laser beam is obliquely projected upon the object. On a disk 9, which is rotated at a fixed angular velocity and, the rotational angle of which is detected by means of an encoder 18, a plurality of PSDs(position sensitive defectors) 11 having different heights are arranged so that the PSDs 11 can detect reflected light while the disk 9 is rotated by one round. The spatial coordinate value of the detecting position of each PSD is found from the detected value and detected position of the encoder 18 and the spatial linear expression of the reflected light is calculated by using the detected value and detected position. Then the spatial coordinate value of the irradiated point and the direction cosine of the normal line are calculated from the spatial linear expression of the incident light.;COPYRIGHT: (C)1998,JPO