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:
Jun. 28, 2022
Filed:
Jan. 19, 2021
Canon Kabushiki Kaisha, Tokyo, JP;
CANON KABUSHIKI KAISHA, Tokyo, JP;
Abstract
Provided is a position measurement apparatus in which a measurement error in a target is reduced. A position measurement apparatus measuring a position of a target includes an illumination unit configured to illuminate the target with illumination light including light of a first wavelength and light of a second wavelength different from the first wavelength, a measurement unit configured to measure the position of the target by detecting light from the target illuminated with the illumination light, and a control unit configured to adjust a ratio of a light intensity of the first wavelength to a light intensity of the second wavelength such that a measurement error varying depending on the position of the target in the measurement unit is reduced.