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:
Dec. 24, 2013
Filed:
Mar. 02, 2012
Kazuo Watabe, Yokohama, JP;
Hideaki Okano, Yokohama, JP;
Takashi Usui, Saitama, JP;
Chikara Tanioka, Yokohama, JP;
Akihito Ogawa, Fujisawa, JP;
Kazuaki Doi, Kawasaki, JP;
Kazuo Watabe, Yokohama, JP;
Hideaki Okano, Yokohama, JP;
Takashi Usui, Saitama, JP;
Chikara Tanioka, Yokohama, JP;
Akihito Ogawa, Fujisawa, JP;
Kazuaki Doi, Kawasaki, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
According to one embodiment, a pickup head includes a plurality of light sources, a first objective lens, second objective lens, a driving unit, a first control unit, a second control unit, light receiving units. The first objective lens focuses a first light beam at a first recording layer. The second objective lens focuses a second light beam at a second recording layer. The driving unit moves the first objective lens and the second objective lens in a first direction and a second direction. The first control unit corrects displacement from target track along the first direction. The second control unit controls a moving direction of a position of the second light spot in the second direction.