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:
Sep. 07, 2004
Filed:
Jul. 10, 2002
Youhei Fujishima, Ageo, JP;
Hironori Ikezawa, Fukaya, JP;
Toshihiko Ozawa, Fukaya, JP;
Yasuhiro Omura, Kumagaya, JP;
Takeshi Suzuki, Ageo, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A projection optical system in which an image of a first surface is projected onto a second surface based on a light beam having a predetermined wavelength. The projection optical system having at least one isometric system refractive member made of an isometric system crystal material. The isometric system crystal material transmits a light beam having the predetermined wavelength. The projection optical system also has an amorphous refractive member made of an amorphous material for compensating deterioration of optical performance due to intrinsic birefringence of the isometric system refractive member.