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:
Nov. 09, 2021
Filed:
Jan. 24, 2020
Canon Kabushiki Kaisha, Tokyo, JP;
Hironori Maeda, Saitama, JP;
Ken Minoda, Utsunomiya, JP;
CANON KABUSHIKI KAISHA, Tokyo, JP;
Abstract
The present invention provides a measurement apparatus that measures a position of an object, including an illumination system configured to illuminate the object with illumination light, an image forming system configured to form, on a photoelectric conversion device configured to detect an image of the object, an image of detected light from the object, and a separation system including a reflective polarizer and a λ/4 plate arranged between the illumination system and the image forming system, and configured to separate the illumination light and the detected light via the reflective polarizer and the λ/4 plate, wherein the separation system includes at least one optical member arranged between the reflective polarizer and the λ/4 plate, and each of the illumination system and the image forming system includes a transmission polarizer.