Surface pit detection system and method
AssigneeQC Optics, Inc.
InventorsGeorge S. Quackenbos, Jay L. Ormsby, Eric T. Chase, Sergey V. Broude, Koichi Nishine
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Abstract
An apparatus and method for uniquely detecting pits on a smooth surface by irradiating an area of the surface; separately sensing radiation scattered from the surface in the near-specular region indicative of a pit and in the far-specular region indicative of a flaw and producing signals representative thereof; normalizing the near-specular signal with respect to the far-specular signal to indicate a pit; and discriminating the near-specular components of the normalized signal representative of surface pits.
Claims21
A detection system for uniquely defining pits on a smooth surface comprising:
- means for directing a beam of radiation to a surface;
- means for separately sensing radiation scattered from the surface in the near-specular region and in the far-specular region and producing signals representative thereof;
- means, responsive to said means for sensing, for normalizing the near-specular signal with respect to the far-specular signal to provide a normalized near-specular signal;
- and
- means for discriminating the near-specular components of said normalized signal representative of surface pits.
A detector apparatus for uniquely defining pits on a smooth surface, comprising:
- means for separately sensing radiation scattered from the surface in the near-specular region and in the far-specular region and producing signals representative thereof;
- and
- means, responsive to said means for sensing, for normalizing the near-specular signal with respect to the far-specular signal to provide a near-specular signal;
- and
- means for discriminating the near-specular components of said normalized signal representative of surface pits.
A method of uniquely detecting pits on a smooth surface, comprising:
- irradiating an area of a surface;
- separately sensing radiation scattered from the surface in the near-specular region indicative of a pit and in the far-specular region indicative of a flaw and producing signals representative thereof;
- normalizing the near-specular signal with respect to the far-specular signal;
- and
- discriminating the near-specular components of the normalized signal representative of surface pits.
Dependencies are inferred from the claim text.