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. 16, 2012
Filed:
Dec. 23, 2010
Kazuhiko Nemoto, Kanagawa, JP;
Midori Kanaya, Tokyo, JP;
Katsuhiro Seo, Kanagawa, JP;
Tamotsu Ishii, Chiba, JP;
Kazuhiko Nemoto, Kanagawa, JP;
Midori Kanaya, Tokyo, JP;
Katsuhiro Seo, Kanagawa, JP;
Tamotsu Ishii, Chiba, JP;
Sony Corporation, Tokyo, JP;
Abstract
Provided is an optical pickup including: a light-source emitting a light-beam; an objective lens collecting the light-beam on a desired recording layer among one or two recording layers or more installed in an optical disc and where spirally- or concentrically-shaped tracks are formed; a lens-moving unit moving the objective lens in a tracking direction toward at least an inner-circumference or outer-circumference side; a light splitting device splitting a reflected light-beam into reflected light-beams and propagating the light-beams; a light-detecting device generating central, inner-circumference-side, and outer-circumference-side light-detecting signals according to received light amounts thereof by central, inner-circumference-side, and outer-circumference-side light-detecting areas, receiving central, inner-circumference-side, and outer-circumference-side portions of an image of the reflected light-beam in the radial direction and allowing a signal processing unit to generate a tracking error signal by using the inner-circumference-side and outer-circumference-side-light-detecting signals, being added with a product of a predetermined coefficient and the central-light-detecting signal.