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. 30, 2014
Filed:
Oct. 17, 2012
Canon Kabushiki Kaisha, Tokyo, JP;
Toshiki Iwai, Utsunomiya, JP;
Kazuhiko Mishima, Utsunomiya, JP;
Hironori Maeda, Utsunomiya, JP;
Ken Minoda, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A detector includes an illumination optical system that illuminates a first diffraction grating having a period in each of a first direction and a second direction different from the first direction, and a second diffraction grating having a period in the second direction different from the period of the first diffraction grating in the second direction. A detection optical system detects diffracted light diffracted by the first diffraction grating and the second diffraction grating. The detection optical system includes a photoelectric conversion element and a guide portion arranged on a pupil plane of the detection optical system. The guide portion guides, to the photoelectric conversion element, the light diffracted by the first diffracting grating and the second diffraction grating. The diffracted light diffracted by the second diffraction grating enters a position different from the guide portion on the pupil plane of the detection optical system.