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:
May. 01, 2001
Filed:
Dec. 08, 1999
Applicant:
Inventor:
Yuichi Osakabe, Utsunomiya, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B 7/02 ; H01J 3/14 ;
U.S. Cl.
CPC ...
G02B 7/02 ; H01J 3/14 ;
Abstract
An optical apparatus includes an optical system having optical elements, an enclosure, enclosing the optical system, for keeping a gas-tight environment inside the enclosure, and a pressure absorber which absorbs variations in differential pressure between the inside and the outside of the enclosure, while maintaining the gas-tight environment in the enclosure during at least one of transportation and storage of the optical apparatus. The optical system is one of a projection optical system and an illumination optical system of an exposure apparatus, and the inside of the enclosure is filled with one of an inert gas and a low-oxygen content gas.