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:
Jul. 30, 2013
Filed:
Feb. 15, 2012
Tomoto Kawamura, Yokohama, JP;
Hiroshi Ogasawara, Yokohama, JP;
Kotaro Oishi, Fujisawa, JP;
Yoshio Okamoto, Yokohama, JP;
Tomoto Kawamura, Yokohama, JP;
Hiroshi Ogasawara, Yokohama, JP;
Kotaro Oishi, Fujisawa, JP;
Yoshio Okamoto, Yokohama, JP;
Hitachi Media Electronics Co., Ltd., Iwate, JP;
Abstract
An optical head capable of recording or playing back optical discs is provided. The optical disc comprises a light source to emit a beam, an objective to focus the beam on an optical disc, a beam dividing element having a plurality of divided areas with which to divide a cross section of the beam reflected from the optical disc, and a light detector to receive the beams divided by the beam dividing element, wherein the beam dividing element has in at least one of the plurality of areas an aberration imparting function of imparting an astigmatism or defocus aberration to a beam passing through that area.