Patent ID: 7557919
Filing Date: 2009-07-07
Classification: G01B

Abstract:
1. An apparatus for detecting a position of a substrate, comprising: a base part; a substrate holding part which is provided above said base part, for holding an approximately disk-shaped substrate; an imaging part for acquiring a substrate image including a part of an edge of said substrate, a position of said substrate being fixed relatively to said base part; a rotation mechanism for rotating an image pickup area of said imaging part around a predetermined central axis to move said image pickup area along said edge, said central axis being perpendicular to a main surface of said substrate and fixed relatively to said base part; an imaging control part which picks up three or more substrate images at three or more image pickup positions around said central axis by controlling said imaging part and said rotation mechanism, and outputs said three or more substrate images, each of which includes a part of said edge of said substrate; and a substrate position calculation part for obtaining a relative position of said substrate to said base part in directions parallel to said main surface of said substrate, on the basis of said three or more substrate images.