Patent ID: 7391523
Filing Date: 2008-06-24
Classification: G01B

Abstract:
1. An apparatus for determining the curvature, relative tilt and/or surface quality of a sample by sequentially analyzing fractional portions of the sample surface, said apparatus comprising: a laser source that produces a single beam of laser light; an optical splitting device that transforms said single laser beam into an incident array of plural, parallel laser beams separated one from another by a known distance; alignment optics that directs said incident array toward a discrete fractional portion of the sample surface and reflecting therefrom a reflected array of laser beams; a detector positioned to receive said reflected array that measures the position of individual laser beams in said reflected array to calculate curvature, relative tilt and/or surface quality of the fractional portion of the sample surface; means for preventing over-saturation of said detector by controlling at least one of the light sensitivity of said detector and the light intensity of said incident array; a data processor; scanning means that moves said incident array relative to the sample surface to progressively scan sequential fractional portions of the sample surface while said data processor compiles a continuous map of the sample surface curvature, relative tilt and/or surface quality; and steering optics disposed optically between the sample surface and said detector that continually aims said reflected array onto said detector, whereby when defects in the sample surface cause said reflected array to stray out of alignment, the array is steered back to a targeted condition upon said detector for continuous measurement while a map is compiled of the sample surface curvature, relative tilt and/or surface quality.