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. 08, 1992
Filed:
Dec. 12, 1991
Applicant:
Inventors:
Yoshiko Tezuka, Saitama, JP;
Keiichi Kuba, Hachioji, JP;
Assignee:
Olympus Optical Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
355 53 ; 355 67 ; 359742 ;
Abstract
The present invention relates to a projection lens system well-fit for baking integrated circuit patterns onto silicon wafers using a light source having wavelengths ranging from an ultraviolet wavelength zone to a vacuum ultraviolet wavelength zone. This projection lens system is characterized by comprising a plurality of lens elements including a Fresnel lens element having negative dispersion characteristics, said Fresnel lens being located at a position lying somewhere in said projection lens system with the exception of the pupil thereof and satisfying the following condition: