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:
Oct. 16, 2007
Filed:
Nov. 26, 2004
Applicant:
Seima Kato, Utsunomiya, JP;
Inventor:
Seima Kato, Utsunomiya, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01B 11/02 (2006.01); G01B 9/02 (2006.01);
U.S. Cl.
CPC ...
Abstract
A measuring method for measuring an interference fringe includes the steps of generating a reference wave as a result of transmission through a slit or pinhole in a mask of a portion of light that has passed a target optical system, generating the interference fringe between the reference wave and a wave of another portion of light that has passed the target optical system and contains aberration information of the target optical system, determining whether contrast of the interference fringe is higher than a predetermined threshold, and exchanging the pinhole or the slit when the contrast is below the predetermined threshold.