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:
Feb. 10, 1998
Filed:
Jan. 27, 1997
Koichi Sentoku, Kanagawa-ken, JP;
Kenji Saitoh, Atsugi, JP;
Hiroshi Osawa, Yokohama, JP;
Masanobu Hasegawa, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A position detection apparatus and method detects the relative positional relationship between first and second objects facing each other in a facing direction. First, second and third marks each serving as a physical optical element are provided on the first object, while a fourth mark serving as a physical optical element is provided on the second object. A light projector projects light onto the first and second objects A light detector detects a first light beam diffracted by the first mark and reflected by the second object, a second light beam diffracted by the second mark and reflected by the second object, and a third light beam diffracted by the third and fourth marks. A first position detector detects the relative positional relationship between the first and second objects in the facing direction based on signals representing the first and second light beams from the light detector. A second position detector detects the relative positional relationship between the first and second objects in a direction perpendicular to the facing direction based on signals representing the first, second and third light beams from the light detector.