Patent ID: 7612873
Filing Date: 2009-11-03
Classification: G01B,G01L

Abstract:
1. A surface form measuring apparatus for measuring surface form of an object, comprising: a light source for emitting a light; an optical system for directing said light emitted from said light source to an irradiation region on an object through an objective lens and directing a reflected light reflected on said irradiation region to a predetermined position through said objective lens; a light shielding pattern positioned at a position almost optically conjugate to an aperture stop position on an optical path from said light source to said irradiation region; an imaging part for acquiring an image of said light shielding pattern formed on said predetermined position; a gradient vector calculation part for obtaining a gradient vector indicating a normal direction of said irradiation region on the basis of an output of said imaging part; a moving mechanism for moving said irradiation region relatively to said object; and a surface form calculation part for obtaining surface form of said object on the basis of gradient vectors in a plurality of areas on said object, said gradient vectors being obtained by said gradient vector calculation part.