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:
Jun. 12, 2012
Filed:
Aug. 17, 2009
Seiichi Kato, Tsuchiura, JP;
Katsuhiko Kimura, Kasumigaura, JP;
Takahiro Yamaguchi, Yokohama, JP;
Yoshiro Konishi, Yokohama, JP;
Seiichi Kato, Tsuchiura, JP;
Katsuhiko Kimura, Kasumigaura, JP;
Takahiro Yamaguchi, Yokohama, JP;
Yoshiro Konishi, Yokohama, JP;
Hitachi Media Electronics Co., Ltd., Iwate, JP;
Abstract
An objective lens actuator, being suitable for a thin-sized optical pickup and a thin-sized optical disc apparatus, comprises: an objective lens for focusing a light upon a recording surface of an optical disc; and a driving mechanism including a focusing coil, tracking coils, and a magnetic circuit, for operating the objective lens into a focusing direction of approaching/receding to/from the optical disc, and into a tracking direction of a radius of the optical disc, wherein the magnetic circuit has a first magnet and a second magnet putting the objective lens therebetween, and one of the magnets is short of length in the focusing direction and is long in length in the tracking direction, comparing to the other magnet, thereby bringing an unnecessary moment, which is applied upon a moving part including the objective lens therein, to be small, and suppressing inclination or tilt and vibration of the objective lens.