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:
Jan. 08, 2013
Filed:
Jan. 06, 2010
Chidane Ouchi, Utsunomiya, JP;
Chidane Ouchi, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A wavefront-aberration-measuring device measures wavefront aberration of a to-be-tested optical system and includes a diffraction grating that splits light transmitted through the optical system, a detecting unit that detects interference fringes produced by beams of the split light, an arithmetic unit that calculates the wavefront aberration from the detected interference fringes, an image-side mask insertable into and retractable from an image plane of the optical system, and an illuminating unit that incoherently illuminates the image-side mask. The image-side mask has an aperture with a diameter larger than λ/2NA, where λ denotes a wavelength of the illuminating unit and NA denotes a numerical aperture of the to-be-tested optical system. The arithmetic unit calculates the wavefront aberration of the optical system from the interference fringes detected with the image-side mask being retracted from the image plane and the interference fringes detected with the image-side mask being in the image plane.