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. 16, 2014
Filed:
Jun. 24, 2013
Canon Kabushiki Kaisha, Tokyo, JP;
Masahiko Mizoguchi, Kawasaki, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
Detection precision is improved by reducing a detection error of a change in position of a target. A correction value derivation apparatus is provided for deriving a correction value used in correction of a displacement amount derived based on an encoder signal indicating a change in position of a movable portion as a target. A displacement amount derivation unit is configured to derive a detected displacement amount of the movable portion based on the encoder signal. A displacement velocity derivation unit is configured to derive a detected displacement velocity based on the detected displacement amount derived by the displacement amount derivation unit. An average displacement velocity calculation unit is configured to calculate an average displacement velocity over a predetermined displacement range. A correction value derivation unit is configured to derive the correction value based on the detected displacement velocity and the average displacement velocity.