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:
Jan. 04, 1983
Filed:
Dec. 03, 1980
Michel Lacombat, Paris, FR;
Thomson-CSF, Paris, FR;
Abstract
An optical system for aligning two patterns in which the alignment takes place in two phases. In the first phase, the first pattern is aligned with respect to a third fixed intermediate pattern, forming a reference, and during the second phase the second pattern is aligned with respect to this third pattern. The first pattern is formed by a pair of alignment reference marks and the third pattern comprises a first pair of complementary reference marks. The second pattern is also formed by a pair of alignment reference marks and the third pattern comprises a second pair of complementary reference marks. In a preferred embodiment, these latter reference marks are formed by optical networks. The projection of one network on the complementary network produces orders of diffraction which are detected by opto-electronic means.