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:
Apr. 24, 2012
Filed:
Oct. 06, 2010
Shigeharu Kimura, Yokohama, JP;
Shigeharu Kimura, Yokohama, JP;
Hitachi Media Electronics Co., Ltd., Iwate-ken, JP;
Abstract
An optical pickup device capable of eliminating interlayer crosstalk which is responsible for fluctuation in control signals and error rate in data signals, thereby ensuring stable action for a multilayered recording disc with a narrow interlayer spacing. The reflected beam coming from the multilayered disc is divided along the central line into two parallel portions by the dividing optical system and then condensed. The reflected beam coming from the active layer, which has been condensed, is reflected by the reflecting plane whose reflecting region is limited and the thus reflected beam is detected by the optical detector. The reflected beam coming from other layers is not reflected by the reflecting plane, so that interlayer crosstalk is reduced.