Patent Number: 8,797,515

Title: Deformation measuring apparatus and deformation measuring method

Abstract: An apparatus and a method capable of measuring large deformation with a high accuracy and dynamically, using speckle interference, utilizes an optical path where one laser beam out of two laser beams becomes non-collimated light and a plane parallel transparent plate, and can form carrier fringes. More specifically, the transparent plate is arranged on the optical path where the non-collimated light is formed, or is removed from the optical path, or a refractive index, or a thickness of the transparent plate arranged on the optical path, or a tilt angle relative to an optical axis is changed. The phase analysis can be performed from fringe images corresponding to the deformation, by performing repetitively the above-described processing and acquisition of the speckle interference pattern.

Inventors: Sugimoto; Takashi (Yokohama, JP)

Assignee: Canon Kabushiki Kaisha

International Classification: G01L 1/24 (20060101); G01B 11/30 (20060101); G01B 11/24 (20060101); G01B 11/02 (20060101)

Expiration Date: 8/05/12018