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. 31, 2006
Filed:
Dec. 24, 2003
Chiaki Terasawa, Tochiqi, JP;
Chiaki Terasawa, Tochiqi, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A catoptric projection optical system for projecting a reduced size of a pattern on an object surface onto an image surface includes eight mirrors and forms an intermediate image between the sixth mirror and the seventh mirror on an optical path, wherein a position in a height direction of a principal ray from an optical axis at each mirror displaces, and a displacement direction from the first mirror to the fourth mirror is reverse to that from the fifth mirror to the eight mirror, wherein the second mirror to the fifth mirror are a concave mirror, a convex mirror, a concave mirror and a concave mirror, and the seventh mirror to the eighth are a convex mirror and a concave mirror, and wherein the second mirror of the eight mirrors is located closest to the object surface side.