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:
Aug. 23, 2011
Filed:
Apr. 24, 2006
Chidane Ouchi, Utsunomiya, JP;
Akihiro Nakauchi, Utsunomiya, JP;
Seima Kato, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A measuring apparatus includes a pinhole mask, located on an object plane of an optical system to be measured, and having a plurality of pinholes for generating a spherical wave from a measuring light beam, and a diffraction grating for splitting the measuring light beam that has passed the pinhole mask and the optical system, in which Lg=m·Pg/λ is met, where Pg is a grating pitch of the diffraction grating, λ is a wavelength of the measuring light beam, m is an integer other than zero, and Lg is a distance between the diffraction grating and an image plane of the optical system. The measuring apparatus detects an interferogram formed by interference between a plurality of the measuring light beams split by the diffraction grating. The plurality of measuring light beams includes an aberration of the optical system.