Patent ID: 6927864
Filing Date: 2005-08-09
Classification: G01B

Abstract:
1. An optical system for determining a height of a surface feature of a surface under test, comprising: a first imaging subsystem aligned at a first predetermined nonzero and non-perpendicular angle with respect to a surface under test for receiving a first line image crossing a direction of optical translation between said surface under test and said optical system and having a narrow field of view projecting a line of sight along said first predetermined angle toward said surface under test, whereby said first imaging system only receives light scattered along said line of sight by vertical projections of said surface under test; a second imaging subsystem aligned at a second predetermined angle with respect to said surface under test for receiving a second line image; a scanning subsystem for generating said optical translation; and a processor coupled to said first and second imaging subsystems for synchronizing said first image and said second image in time and computing said height of said surface feature in conformity with the deviations between said first image and said second image generated as the scanning subsystem moves an edge of said surface feature within the optical paths of said first and said second imaging subsystems.