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. 23, 2012
Filed:
Oct. 31, 2008
Tomoyuki Ueno, Itami, JP;
Masato Hasegawa, Itami, JP;
Tomoyuki Ueno, Itami, JP;
Masato Hasegawa, Itami, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
A diffractive optical element () composed of a ceramic, in which the optical characteristics are enhanced by enhancing the machining precision, is composed of an infrared-transmissive ceramic, and prominent portions () and groove portions () are repeatedly formed on a surface of the diffractive optical element (). The average value of the surface roughness Ra within an optical effective area () of the surface of the diffractive optical element is 0.05 μm or less, and the difference in the surface roughness Ra within the optical effective area () of the surface is 0.02 μm or less.