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:
May. 22, 2012
Filed:
Dec. 09, 2009
Applicants:
Shuusuke Tobita, Fujisawa, JP;
Yusuke Ohmura, Utsunomiya, JP;
Inventors:
Shuusuke Tobita, Fujisawa, JP;
Yusuke Ohmura, Utsunomiya, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B 3/08 (2006.01);
U.S. Cl.
CPC ...
Abstract
A surface of a base material of a Fresnel lens has a central area having circular zones arranged therein and an outer area located on the outer side of the central area and having circular-arc zones arranged therein. The pitch of zones in a boundary area between the central area and the outer area and where the zone shape changes is smaller than a basic pitch which is the pitch of the circular and circular-arc zones in the central area and the outer area.