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:
Jan. 01, 2013
Filed:
Jul. 29, 2009
Goro Fujita, Kanagawa, JP;
Hirotaka Miyamoto, Kanagawa, JP;
Kimihiro Saito, Saitama, JP;
Kunihiko Hayashi, Kanagawa, JP;
Goro Fujita, Kanagawa, JP;
Hirotaka Miyamoto, Kanagawa, JP;
Kimihiro Saito, Saitama, JP;
Kunihiko Hayashi, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
An optical disc apparatus includes a light separator configured to separate a light beam emitted from a light source into a main beam and a sub-beam, an objective lens configured to, when the light beam is condensed and irradiated to an optical disc having a uniform recording layer in which a track is formed by record marks, irradiate at least part of the sub-beam to an area where the main beam is not irradiated in a radial direction which is defined as a direction of radius of the optical disc, and a signal generating unit configured to generate a mark layer distance signal, representing a distance between a focus of the light beam and a mark layer to which the track belongs, based on a return light beam resulting from at least one of the main beam and the sub-beam, which has been irradiated to the track.