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:
Mar. 20, 2007
Filed:
Jun. 21, 2005
Hideo Tanaka, Utsunomiya, JP;
Hideo Tanaka, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A positioning apparatus includes first and second stages, a pair of first mirrors having reflective surfaces disposed on the first stage at an acute angle with a vertical axis, a pair of second mirrors disposed on the second stage and having reflective surfaces orthogonal to the vertical axis, a reference structure functioning as a reference for measuring the vertical position of the second stage, a pair of third mirrors disposed on the reference structure and having reflective surfaces orthogonal to the vertical axis, and a pair of interferometers for measuring the vertical position of the second stage using the first, second, and third mirrors.