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:
Sep. 23, 2014
Filed:
Jun. 14, 2012
Ken Minoda, Utsunomiya, JP;
Yoshihiro Shiode, Utsunomiya, JP;
Kazuhiko Mishima, Utsunomiya, JP;
Hironori Maeda, Utsunomiya, JP;
Ken Minoda, Utsunomiya, JP;
Yoshihiro Shiode, Utsunomiya, JP;
Kazuhiko Mishima, Utsunomiya, JP;
Hironori Maeda, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A position detection apparatus includes an illumination optical system for illuminating a first diffraction grating having periods in each of a first direction and a second direction different from the first direction, and a second diffraction grating having a period different from the period in the second direction of the first diffraction grating in the second direction, at an oblique incidence, and a detection optical system for detecting diffracted light from the first diffraction grating and the second diffraction grating, wherein a relative position of the first diffraction grating and the second diffraction grating is detected based on the detected diffracted light, and wherein the illumination optical system includes a plurality of light intensity distributions in the first direction except for on an optical axis of the detection optical system, in a pupil plane thereof.