Patent ID: 7312870
Filing Date: 2007-12-25
Classification: G01B,G01N

Abstract:
1. An optical alignment detection system for detecting the alignment of a first object relative to a second object, the optical alignment system comprising: one or more light blocking regions and one or more non-light blocking regions, both fixed relative to the first object; two or more light sources fixed relative to the second object, the two or more light sources adapted to provide light such that a light beam from at least one of the light sources intersects at least one of the one or more light blocking regions and a light beam from at least one other of the light sources intersects at least one of the one or more non-light blocking regions; one or more detectors for detecting the light beams provided from the two or more light sources; identifying block for identifying which of the two or more light sources provide a light beam that intersects the one or more light blocking regions and/or which of the two or more light sources provide a light beam that intersects the one or more non-light blocking regions; and determining block for determining the alignment of the first object relative to the second object from the identified light source(s).