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. 21, 2008
Filed:
Dec. 22, 2003
Mitsuru Mimori, Kokubunji, JP;
Mitsuru Mimori, Kokubunji, JP;
Konica Minolta Holdings, Inc., Tokyo, JP;
Abstract
An objective optical element for use in an optical pickup apparatus comprises a first optical surface including a first diffractive structure which comprises a plurality of concentric ring-shaped diffractive zones having a center on the optical axis and stepped surfaces arranged to be almost parallel to the optical axis and connecting respective neighboring ring-shaped diffractive zones; and a second optical surface including a second diffractive structure which comprises a plurality of concentric ring-shaped diffractive zones having a center on the optical axis and stepped surfaces arranged to be almost parallel to the optical axis and connecting respective neighboring ring-shaped diffractive zones. The stepped surfaces of the first diffractive structure are arranged to face an optical axis side, and the stepped surfaces of the second diffractive structure are arranged to face an opposite side of the optical axis side.