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:
Oct. 14, 2008
Filed:
Nov. 04, 2005
Tomowaki Takahashi, Yokohama, JP;
Tomowaki Takahashi, Yokohama, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A reflective-type projection optical system has 8 reflective mirrors that form a reduced image of a first surface on a second surface. A first reflective imaging optical system (G) forms an intermediate image of the first surface, and a second reflective imaging optical system (G) forms an image of the intermediate image on the second surface. The first reflective imaging optical system has, from the first surface side in order of light beam incidence, a first reflective mirror (M), a second reflective mirror (M), a third reflective mirror (M), and a fourth reflective mirror (M). The second reflective imaging optical system has, from the first surface side in order of light beam incidence, a fifth reflective mirror (M), a sixth reflective mirror (M), a seventh reflective mirror (M), and an eighth reflective mirror (M). At least one of the reflective surfaces of these 8 reflective mirrors is composed of a spherical surface.