| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a position measurement device having an improved measurement accuracy at a low cost. <P>SOLUTION: A position measurement device (32-36) includes multiple concave portions (18) arranged on a concentric circle with a predetermined concave portion center position as the center on the outer wall (2d) of an object (2); a concave portion (16) having the multiple concave portions (18); a light source portion (32) that radiates light to the object (2); a light receiving portion (33a) that receives light from the object (2); and concave portion measurement means (36d) that measures a position of the concave portion (16) of the object (2) based on the concentration distribution of the light reflected from the concave portion (16). <P>COPYRIGHT: (C)2012,JPO&INPIT |
