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:
Dec. 28, 1999
Filed:
Apr. 27, 1998
Nikon Corporation, Tokyo, JP;
Abstract
A high-performance dioptric reduction projection lens and projection exposure apparatus and projection exposure method using same. The projection lens includes six lens groups and has a positive negative positive negative positive refractive power arrangement. The third and fifth lens groups have overall positive refractive power and include at least three lens elements having positive refractive power. The fourth lens group has negative refractive power and includes at least three lens elements having negative refractive power. At least one lens element in either the fourth lens group or the fifth lens group includes an aspheric surface. The projection lens preferably satisfies at least one of a number of design conditions.