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:
Feb. 15, 2011
Filed:
Feb. 11, 2009
Naoto Hayashi, Utsunomiya, JP;
Shinichiro Hirai, Saitama, JP;
Naoto Hayashi, Utsunomiya, JP;
Shinichiro Hirai, Saitama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
The present invention provides an exposure apparatus including a measuring unit which includes an imaging optical system configured to guide light having propagated through a projection optical system to an image sensor, and is configured to measure the overall birefringence of the imaging optical system and the projection optical system, a calibration unit which is set on a side of an object plane of the projection optical system in order to measure a birefringence of the imaging optical system, and is configured to reflect the light from the measuring unit back to the measuring unit without using the projection optical system, and a calculation unit configured to isolate, from the result of measuring the overall birefringence, the birefringence of the imaging optical system measured by the measuring unit, thereby calculating the birefringence of the projection optical system.