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. 14, 2015
Filed:
Oct. 18, 2011
Yasuhiro Omura, Kumagaya, JP;
Yasuhiro Omura, Kumagaya, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A catadioptric projection objective for imaging a pattern provided in an object plane of the projection objective onto an image plane of the projection objective. The projection objective includes a first objective part that includes one or more refractive optical elements to image the pattern provided in the object plane into a first intermediate image, a second objective part that consists of reflective optical elements including at least one concave mirror to image the first intermediate image into a second intermediate image, and a third objective part that includes one or more refractive optical elements to image the second intermediate imaging onto the image plane. The projection objective includes at lease one double asphere having a first aspheric surface and a second aspheric surface immediately adjacent to the first aspheric surface, the double asphere being formed by facing adjacent aspheric surfaces of two consecutive lenses.