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:
Jun. 17, 2014
Filed:
Dec. 09, 2013
Panasonic Corporation, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
An optical element has at least one surface divided into a plurality of regions and includes: a first region configured to converge light with a wavelength λonto a storage surface of a first optical disc and converge light with a wavelength λonto a storage surface of a second optical disc; and a second region formed around the outer circumference of the first region and configured to converge light with the wavelength λonto the storage surface of the first optical disc. The second region has a concave-convex structure concentrically formed on an aspheric surface and having a cross section being a saw teeth shape. The concave-convex structure is formed by a plurality of different saw teeth shapes, and the plurality of different saw teeth shapes respectively give different phase differences corresponding to substantially integer multiples of the wavelength λfor light with the wavelength λ