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:
Dec. 23, 2025
Filed:
Jun. 02, 2023
Lasertec Corporation, Kanagawa, JP;
LASERTEC CORPORATION, Yokohama, JP;
Abstract
A calculation method according to the present disclosure is a calculation method of calculating a shear amount produced by a predetermined optical element which is arranged on an optical path of an image-capturing optical system. The calculation method includes a step of capturing a plurality of interference contrast images of a quadric surface included in an object surface by the image-capturing optical system while changing a phase difference between two rays of divided light, a step of obtaining a phase distribution from the plurality of interference contrast images by a phase shift method, a step of measuring a fringe interval of interference fringes due to the quadric surface based on the phase distribution, and a step of calculating the shear amount of the optical element based on a constant in a formula expressing the quadric surface and the fringe interval.