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:
Aug. 11, 1992
Filed:
Dec. 24, 1990
Tetsuo Taniguchi, Kawasaki, JP;
Kazuaki Suzuki, Kawasaki, JP;
Toshihiko Tsuji, Kawasaki, JP;
Masato Hatasawa, Yokohama, JP;
Nikon Corporation, Tokyo, JP;
Abstract
In a projection-type optical apparatus in which a projection optical system projects an image of an object upon a substrate, a position detecting sensor mechanically connected to the projection optical system detects the position of the projection optical system relative to the substrate along the optical axis of the projection optical system. A displacement measuring device measures relative displacement between the position detecting sensor and the projection optical system along the optical axis. The substrate is brought into coincidence with an optimum image forming plane of the projection optical system on the basis of the position detected by the position detecting sensor and the displacement measured by the displacement measuring device.