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:
Apr. 23, 2002
Filed:
Jan. 31, 2000
Applicant:
Inventors:
Shigeru Sakuma, Chigasaki, JP;
Masaki Shiozawa, Sagamihara, JP;
Assignee:
Nikon Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03B 2/742 ; G03B 2/754 ; G02B 1/314 ; F21V 9/06 ;
U.S. Cl.
CPC ...
G03B 2/742 ; G03B 2/754 ; G02B 1/314 ; F21V 9/06 ;
Abstract
An optical member for photolithography made of a calcium fluoride crystal exhibits an internal transmittance of 99.5%/cm or greater with respect to light having a specific wavelength of 185 nm or shorter.