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. 03, 2013
Filed:
May. 19, 2011
Shinichiro Takahama, Matsudo, JP;
Masahiko Igaki, Yokohama, JP;
Yasuyuki Miyaoka, Yokohama, JP;
Yasumichi Arimitsu, Yokohama, JP;
Shinichiro Takahama, Matsudo, JP;
Masahiko Igaki, Yokohama, JP;
Yasuyuki Miyaoka, Yokohama, JP;
Yasumichi Arimitsu, Yokohama, JP;
Canon Kabushiki Kaisha, , JP;
Abstract
A displacement detection apparatus includes a scaleon which marks are disposed, first and second position detection sensorsanddetecting positions of the marks, and a processorperforming a calculation processing of an output signal from each of the first and second position detection sensorsand. The first and second position detection sensorsandare disposed at a distance L from each other to be movable relative to the scale. The processorcalculates a correction value P' of a mark pitch P of the marksusing the distance L, a first time Trequired for K marks of the marksto pass a detection position, and a second time Trequired for a specific mark of the marks, which are measured at the same time of the first time T, to move the distance L.