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. 11, 2009
Filed:
Mar. 01, 2006
Kenji Yamazoe, Utsunomiya, JP;
Seiji Takeuchi, Utsunomiya, JP;
Akiyoshi Suzuki, Tokyo, JP;
Canon Kabushiki Kaisha, , JP;
Abstract
An exposure apparatus includes an illumination optical system for illuminating the reticle using the ultraviolet light from the light source, and a polarization measuring unit measuring the polarization state of the ultraviolet light, the polarization measuring unit including an optical unit for providing at least three different phase differences to the ultraviolet light that has passed at least part of the illumination optical system, a polarization element for providing a different transmittance in accordance with a polarization state of the ultraviolet light that has passed the optical unit, and an image pickup device for detecting a light intensity of the ultraviolet light that has passed the polarization element, the polarization measuring unit measuring the polarization state of the ultraviolet light that has passed the at least part of the illumination optical system based on a detection result of the image pickup device.