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:
May. 06, 2003
Filed:
Aug. 01, 1997
Yuichi Yamada, Utsunomiya, JP;
Shigeyuki Uzawa, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A surface position detecting method wherein an object having a region with a pattern structure formed thereon is relatively scanned relative to a surface position detecting device and surface positions of the object at plural detection points in the region are detected by use of the surface position detecting device. The method includes steps of detecting an error related to the detection through the surface position detecting device, with respect to each of the detection points, which error is attributable to a difference in pattern structure at the detection points in the region, detecting the surface positions of the object at the detection points through the surface position detection device in synchronism with a relative scan of the object and the surface position detecting device, the detection of the surface positions being performed by a sensor, which is arranged to perform the detection in accordance with a predetermined cycle, and determining a timing for the detection by the surface position detecting device in accordance with the relative position of the object and the surface position detecting device during the relative scan. The timing is determined while the detection cycle of the sensor is held synchronized with the relative position of the object and the surface position detecting device.