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. 06, 2010
Filed:
Dec. 21, 2004
Tomowaki Takahashi, Yokohama, JP;
Tomowaki Takahashi, Yokohama, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A projection optical system comprises eight reflectors and forms a reduced image of a first surface () onto a second surface (). It comprises a first reflective imaging optical system (G) for forming an intermediate image of the first surface and a second reflective imaging optical system (G) for forming an image of the intermediate image onto the second surface. The first reflective imaging optical system includes a first reflector (M), a second reflector (M), a third reflector (M), and a fourth reflector (M) successively as light enters from the first surface side. The second reflective imaging optical system includes a fifth reflector (M), a sixth reflector (M), a seventh reflector (M), and an eighth reflector (M) successively as light enters from the first surface side. This realizes a reflective projection optical system which can favorably correct aberrations while having a favorable reflection characteristic with respect to X-rays and keeping the reflectors from becoming bulky.