Optics: measuring and testing – By particle light scattering – With photocell detection
Patent
1992-10-02
1995-04-04
Turner, Samuel A.
Optics: measuring and testing
By particle light scattering
With photocell detection
356356, G01B 902
Patent
active
054042208
ABSTRACT:
A method and an apparatus for measuring a very small displacement of an object. The first and second beat signals are produced by light beams of different frequencies diffracted by a diffraction grating. The phase difference between the first and second beat signals is detected, thereby measuring the relative displacement of the diffraction grating.
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Ishizuka Koh
Nishimura Tetsuharu
Nose Hiroyasu
Takeuchi Seiji
Yoshii Minoru
Canon Kabushiki Kaisha
Turner Samuel A.
Wolfe Russell C.
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