Patent ID: 6100980
Filing Date: 2000-08-08
Classification: G01B

Abstract:
A magnification calibration apparatus, comprising:an optical system optically coupled to an object surface for forming an image of the object surface;a detector for detecting the image of the object surface;a movable support for supporting the object surface, the movable support being configured to laterally move the object surface by a predetermined distance from a first lateral position to a second lateral position;a reference point recognition unit for, at each of the first and second lateral positions of the object surface, detecting the position of the image of an imaginary reference point on the object surface as a position in a detector coordinate system fixed to the detector in accordance with the image detected by the detector; anda computation unit for deriving a correspondence between an object coordinate system at the object surface and the detector coordinate system from the detected positions of the image in the detector coordinate system at the first and second lateral positions of the object surface and from the predetermined distance by which the object surface is moved from the first lateral position to the second lateral position by the movable support.