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. 02, 2013
Filed:
Mar. 09, 2010
Applicant:
Yuhei Sumiyoshi, Utsunomiya, JP;
Inventor:
Yuhei Sumiyoshi, Utsunomiya, JP;
Assignee:
Canon Kabushiki Kaisha, , JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03B 27/68 (2006.01); G03B 27/32 (2006.01);
U.S. Cl.
CPC ...
Abstract
A projection optical system is configured to project an image of an object plane onto an image plane, and includes a first optical element having an aspheric shape that is rotationally asymmetric with respect to an optical axis, a moving unit configured to move the first optical element in a direction perpendicular to the optical axis, and a second optical element fixed on the optical axis, and configured to reduce an optical path length difference caused by an aspheric surface of the first optical element, the second optical element having no aspheric shape complement to the aspheric shape of the first optical element.