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. 11, 2003
Filed:
Feb. 27, 2001
Yuichi Yamada, Utsunomiya, JP;
Shigeyuki Uzawa, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A surface position detecting system having a surface position detecting device including a light projecting device for projecting light obliquely onto a detection point and a light receiving device for receiving reflection light from the detection point. While an object having a region with a pattern structure is relatively scanned relative to the surface position detecting device, a surface position at plural points within the range is detected. The surface position detecting system includes an optimum value detecting device for projecting, before the surface position detection, light from the light projecting device to each of the plural detection points and for receiving, with the light receiving device, reflection light from the point. The optimum value detecting device detects and memorizes an optimum value of a gain of the light receiving device or a drive current for the light projecting device with respect to each detection point, on the basis of a light reception signal of the light receiving device. The surface position detecting system also includes a setting device for setting an optimum value for a drive current for the light projecting device or a gain of the light receiving device with respect to each of the detection points, for the surface position detection.