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:
Apr. 21, 2009
Filed:
Jun. 01, 2005
Hiroyuki Sugawara, Hitachinaka, JP;
Takeshi Goto, Ebina, JP;
Kounosuke Kitamura, Ebina, JP;
Hiroshi Aoyama, Ebina, JP;
Hiroyuki Sugawara, Hitachinaka, JP;
Takeshi Goto, Ebina, JP;
Kounosuke Kitamura, Ebina, JP;
Hiroshi Aoyama, Ebina, JP;
Hitachi Via Mechanics Ltd., Ebina-shi, JP;
Abstract
A method for determining a position of a reference point in which there is no influence of aberration of a camera lens or the like, but an error caused by a failure in shape of an alignment mark can be reduced. An alignment mark consisting of a plurality of pattern portions (and background portions) centering at a design reference point is provided in advance. Positions of centers of border lines of the patterns are calculated. Obtained coordinate values of the centers are averaged in each axial direction. The averaged coordinate values are regarded as coordinate values of a machining reference point. Thus, even when a defect occurs in any pattern portion, an error caused by the defect is reduced so that the accuracy in machining can be improved.