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:
Jul. 07, 2009
Filed:
Aug. 09, 2007
Yasuhiro Omura, Kainosu, JP;
Hironori Ikezawa, Fukaya, JP;
Yasuhiro Omura, Kainosu, JP;
Hironori Ikezawa, Fukaya, JP;
Nikon Corporation, Tokyo, JP;
Abstract
In a liquid immersion type projection optical system for forming an image of a first plane on a second plane, an optical path between the optical system and the second plane is filled with a liquid having the refractive index larger than 1.5, and the optical system has a boundary optical element whose surface on the first plane side is in contact with a gas and whose surface on the second plane side is in contact with the liquid. The optical system satisfies the condition of 3.2<Nb·Eb/|Rb|<4.0, where Rb is a radius of curvature of the surface on the first plane side of the boundary optical element, Eb an effective diameter of the surface on the first plane side of the boundary optical element, and Nb a refractive index for used light, of an optical material forming the boundary optical element.