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. 25, 1998
Filed:
Oct. 15, 1997
Seiji Miyazaki, Yokohama, JP;
Hiroshi Shirasu, Yokohama, JP;
Kazuaki Saiki, Tokyo, JP;
Tsuyoshi Narabe, Ohmiya, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A pair of reference plates is so arranged as to have a predetermined positional relationship on a carriage that integrally holds a mask and a photosensitive substrate such that the mask and the photosensitive substrate oppose each other on two sides of a projecting optical system. By periodically detecting the positional relationship between the reference plates in the optical axis direction, a variation with time occurring in the detection characteristics of position detecting devices is detected. Both stable image formation characteristics and a high throughput are realized by correcting a driving signal to be supplied to a driving device in accordance with the detected variation.