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:
Mar. 22, 2011
Filed:
Jul. 18, 2008
Hideki Ide, Yokohama, JP;
Masahiro Uekita, Yokohama, JP;
Eijiro Koike, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A diffraction optical element is provided to reduce harmful lights and also suppress deterioration in the optical characteristics of the element. The diffraction optical elementis formed with a plurality of diffraction gratings' and′. From these diffraction gratings, there are selected the diffraction gratings′ and′ whose groove apex angles are less than a predetermined angle. The diffraction gratings′ and′ has chamfer surfaces′ and′ formed on the lower side of respective slanted surfaces′ and′. The chamfer surfaces′ and′ are slanted to the slanted surfaces′ and′, respectively.