The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 12, 2011
Filed:
Feb. 15, 2008
Tomoyuki Miyashita, Utsunomiya, JP;
Takahiro Matsumoto, Utsunomiya, JP;
Hideki Ina, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A shape measuring apparatus for measuring the shape of a measurement target surface includes an interferometer and computer. The interferometer senses interference light formed by measurement light from the measurement target surface and reference light by a photoelectric converter, while changing the light path length of the measurement light or the reference light. The computer Fourier-transforms a first interference signal sensed by the photoelectric converter to obtain a phase distribution and an amplitude distribution, shapes the amplitude distribution, inversely Fourier-transforms the phase distribution and the shaped amplitude distribution to obtain a second interference signal, and determines the shape of the measurement target surface based on the second interference signal.