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:
Nov. 15, 2011
Filed:
Aug. 15, 2008
Taku Tsuboi, Kanagawa, JP;
Eiichi Ueda, Tokyo, JP;
Taku Tsuboi, Kanagawa, JP;
Eiichi Ueda, Tokyo, JP;
Sony NEC Optiarc Inc., Tokyo, JP;
Abstract
An optical pickup apparatus capable of irradiating an optical recording medium having a plurality of recording layers on which a signal is recorded with laser light includes a light source emitting the laser light, a light-concentrating element concentrating the laser light emitted from the light source on the optical recording medium, a phase difference element having a region divided into at least two regions which the laser light reflected by the optical recording medium enters and producing a phase difference between first light and second light reflected by a non-target layer which is not a target of recording or reproduction of the signal out of the plurality of recording layers and entering the at least two regions such that the first and the second light weaken each other, and a photodetector receiving the laser light emitted from the phase difference element.